Are those the only two options for someone who prefers partners of their own gender?
I will allow for three. Marry the opposite sex and be miserable.
Choose to be with the adult you are drawn to ...
Remain celibate and alone.
More importantly, is there any reason to believe that our taste in partners is fundamentally different than our tastes in any other things?
Anytime it has to do with strong emotions and interacting with others, it does.
I have never said that someone couldn't choose to marry someone they are not drawn to OR remain celibate. I am just stating flat out that I know I didn't choose to be attracted to the opposite sex. I can remember as far back as when I was five thinking little boys at school or at Sunday school were cute. I didn't see girls in the same way.
I never could make myself be attracted to someone of the same sex ... because my sexual orientation was not a choice. Why on earth would I believe that others have not had the same experience?
IF a homosexual OR heterosexual choose to remain celibate for reasons of their own, that is spiffy. The problem is when you choose to play mind reader and tell everyone else what and who they are attracted to and what and who they should be attracted to.