We're just a bunch of chemicals thrown together and see what happens. 9 times out of 10 the same thing happens, one in every 10 a random event occurs and it changes the outcome, determined by 1/3 and 6.
Cell fusion is messy and unpredictable. I could have just as easily come out born with no arms as I could have been born non heterosexual.
I supposed I'd say number 5 and 7. While I'm not willing to conclude that people are born a certain sexuality, I am willing to conclude that, for as long as the person can remember, they were a certain sexuality. Thus, I think there is a possibility that sexuality is the result of a particular upbringing or environment, be it consciously or unconsciously achieved.
Deterministic, yes. But that doesn't mean that sexuality can't change over time. I've known of some persons that have evolved from straight to bisexual (and who knows, maybe they'll end up being gay). However, I believe that flexibility is also predetermined; either you're born with it or you don't.
A co,bination theory, i mean of course it is dictated by the hormonal influece that are codify before birth but influenced by the enviroment, but also the society and his moral influence the sexuality(what the different type of sexuality in ages) and in this society-moral i put also the enviroment that influenced the think-way of the people.
Anyone who looks for the One True Explanation for any aspect of human behavior is barking up the wrong tree, and that included any particular "combination". You might be able to identify the building blocks of sexuality in one or another individual, but the last thing I expect would be to be able to identify them for everyone, everywhere, in all times.