Final answer:
There is good scientific evidence indicating that genetic factors and prenatal hormone exposure have an effect on sexual orientation. Research suggests a biological basis to sexual orientation, with genetic contributions and differences in brain and body development being linked to whether a person identifies as heterosexual, homosexual, or bisexual.
Step-by-step explanation:
Regarding the question of which factor has good scientific evidence for an effect on sexual orientation, the correct answer is C) Genetic factors and prenatal hormone exposure. While no scientific consensus exists that singles out one determinant of sexual orientation, evidence suggests that some biological components are at play. Notably, genetic links have been observed that contribute to sexual orientation, with research indicating that genes could account for a significant portion of variability in human sexual orientation. This includes studies pointing to gene-level contributions and observations of differences in brain structure among individuals with different sexual orientations.
Moreover, prenatal hormone exposure is another area where science has indicated a biological component to sexual orientation. The development and function of the body have also been associated with sexual orientation, such as differences in the 2nd to 4th finger length ratio. These findings suggest that sexual orientations may be something individuals are born with rather than primarily shaped by social upbringing, peer influence, or dietary habits.