The poll needs more options. In addition to the two options, there are also theories that kids become homosexual with time (nature versus nurture), that it's a combination of the three, or that it varies from person to person. As neither of the two offered alternatives fit my view, I refrained from voting.
I think I don't know. But I'm sure it's not a conscious choice, and that fundies' "homosexuality therapy" largely not only does not work, but also does more harm than good.