What starts with 'O'?

Going through a diagnostic test with our PreK children we show them the letters of the alphabet, ask them what letters they recognize, what sounds they can make, and what words start with each letter. One of our little ones gets to the letter O, and states the correct letter, and the correct sound. I ask him a word that starts with O, and he states "Oh, snap!"

Gotta give it to him on that one!