The issue of classifying people's sexual orientations is made difficult by the fact that:
a. a relatively high percentage of people report same-gender attraction, yet do not identify themselves as homosexual or bisexual.
b. there are substantially more people who self-identify as homosexual than as bisexual.
c. homosexuals and bisexuals constitute such a small proportion of the population
d. there are substantially more people who self-identify as bisexual than as homosexual