CNN is defending its decision to end Thursday's two-hour slugfest among Democratic presidential contenders with a light-hearted question to Hillary Clinton about jewelry.

The network closed the debate in Las Vegas with a smiley face, directing a college student — who had hoped to ask Clinton about nuclear waste storage — to lob a "diamonds or pearls" softball at the New York senator instead.

On Friday, the student who asked the question told FOXNews.com that she felt hung out to dry and said she was facing criticism from fellow students.

Maria Parra-Sandoval, 22, a senior political science major at the University of Nevada, Las Vegas, said she wanted to ask the Democratic frontrunner where she stood on the proposed Yucca Mountain nuclear repository in Nevada, an issue about which she said she wrote a paper as a finalist for a Truman Scholarship.

Following the student's complaints, CNN released the following statement:

"As a service to our viewers and the candidates, the audience questioners were encouraged not to ask questions about topics that had already been addressed during the debate. The questions, including both Yucca Mountain and the diamonds/pearls question, were entirely the questioner's own.

"Yucca had already been discussed, so with less than two minutes left in the debate, CNN asked the student if she'd like to ask her 'diamonds or pearls' question. The student agreed to ask her question, and it seemed like a light-hearted way to end the two-hour debate."

Yucca Mountain had been discussed earlier in the night, but not by Clinton.

Parra-Sandoval said CNN's Suzanne Malveaux told her right before the end of the debate to go with the following question:

"This is a fun question for you. Do you prefer diamonds or pearls?"

The question got a big laugh, and Clinton answered swiftly:

"Now, I know I'm sometimes accused of not being able to make a choice.

"I want both."

To a roar of applause and more laughter, moderator Wolf Blitzer closed out the night.

Parra-Sandoval said Friday that she had submitted both the diamonds-or-pearls and the nuclear-waste questions, and both were pre-approved, but she said the Yucca Mountain one was the one she wanted to ask. She said she entered the line about diamonds or pearls because she knew CNN was looking for something light-hearted.

"I had no idea the debate was about to end," she said. "I thought that I was supposed to have both of those questions. ... They told me to memorize both of them, so my impression was I was going to ask both."

Parra-Sandoval said she felt Clinton has waffled on Yucca Mountain and she wanted to hear a clear answer.

The student's question came at the end of a debate that some analysts said was soft on Clinton. There was only glancing mention of reports that Clinton's campaign had been planting favorable questions for audience members to ask her, and Clinton faced no direct questions on it.

And after two weeks of giving shifting positions on whether she supports driver's licenses for illegal immigrants, Clinton's one-word response — "No" — went unchallenged by Blitzer. Her hedging on the issue at a debate two weeks ago in Philadelphia has opened her up to intense criticism.

Parra-Sandoval said she's taken some "backlash" since asking the fluff question. She said a woman in the audience who she thinks was another student told her she gave the university a "bad reputation" — for asking the far-from-academic question.

Then, she said, she heard there was a rumor going around campus that she had set back the Chicano movement. Parra-Sandoval, who is Mexican, said that was obviously an exaggeration but she was still shaken up.

"Being the serious student that I am, I thought that I would get to ask the most serious question that I wanted," she said.

The question she wanted to ask Clinton was:

"Yucca Mountain, Nevada, is the proposed site for the country's nuclear repository. Despite scientific evidence that it is a vulnerable site, the federal government continues to push for the plan to move forward. The evidence relied on is unsound and the risks involved in transporting high-level radioactive waste across the country are high. What will you do to ensure that the best site is chosen for the storage of spent nuclear reactor fuel?"

Parra-Sandoval said she got the feeling once the debate ended that CNN already had planned to end the debate on the pearls question. She said her other submitted questions, which were not used, had to do with health care for children and the war in Iraq.