A "nerd" cellist from the smallest state in the union who supports transgendered pageant contestants won the Miss USA pageant Sunday night.

Olivia Culpo, a Boston University sophomore who considers herself a modern-day Audrey Hepburn, will take a year off from her studies to tackle her duties as Miss USA and represent the nation in the 61st Miss Universe contest in December. 

After making it to the final five, the 20-year-old was asked a question about transgender beauty queens during the make-or-break interview round. A transgendered contestant was allowed to compete in another pageant that feeds in to the Miss Universe pageant, as does Miss USA.

"Would you feel it would be fair that a transgender woman wins the Miss USA title over a natural-born woman?" asked Kim Kardashian's brother Rob. 

'She gave a great answer'

- Donald Trump

"I do think that that would be fair, but I can understand that people would be a little apprehensive to take that road because there is a tradition of natural-born women," Culpo said. "But today where there are so many surgeries and so many people out there who have a need to change for a happier life, I do accept that because I believe it's a free country." 

The owner of the Miss USA and Miss Universe pageants, Donald Trump, told FOX News that he vetted all of the questions, including the one about transgendered contestants.

"Whoever gets that one ... that's a tough one," he said he thought after okaying the question. "She gave a great answer."

Culpo said after the pageant that she wasn't put off by the question when she heard it.

"This is a free country and to each their own," she said.

Culpo said she was short and chubby as a girl, but blossomed after a growth spurt. She spent her summers at band camp after learning to play the cello in second grade. Her parents are also musicians, and her love for music saw her perform at Symphony Hall in Boston and Carnegie Hall in New York City.

Culpo is a 2010 graduate of St. Mary Academy Bay View, an all-girls Catholic school in Riverside, where she was a member of the National Honor Society. She said she comes from a big, Italian family and speaks some Italian. On her Twitter account, she describes herself as a nerd and model.

"I was just so surprised, so shocked, so honored to be there," she said of her win.

Rounding out the top five contestants were first runner-up Nana Meriwether of Maryland, second runner-up Audrey Bolte of Ohio, third runner-up Jade Kelsall of Nevada and fourth runner-up Jasmyn Wilkins of Georgia. As Meriwether and Culpo held hands waiting for the winner to be announced, Culpo bit her lip and cringed with anticipation.

Culpo demonstrated an outgoing personality throughout the competition, blowing a kiss and shimmying across the stage during the opening number. She cited Hepburn as her source of inspiration, noting her many years of volunteer work.

"She was beautiful on the outside, but also beautiful on the inside," said Culpo, who sang the chorus of "Funny Face" from her favorite movie of the same name after her win.

Miss Iowa USA Rebecca Hodge was named Miss Congeniality, and Miss Oregon USA Alaina Bergsma was named the most photogenic. They both won $1,000, but didn't make the top 16.

The judge's panel included Chef Cat Cora, TV personality Arsenio Hall and singer Joe Jonas. Andy Cohen and Giuliana Rancic stepped in to host. Miss USA 2011 Alyssa Campanella of California crowned Culpo her successor at the end of the night.

The Associated Press contributed to this report.