In His Research to Determine What Percentage of the Population

In his research to determine what percentage of the population was heterosexual and what percentage was homosexual,why would Alfred Kinsey have avoided asking the question,"Do you identify as gay or straight?"

A) He tried to offset bias in his research sample by having many questions.
B) He believed that people were not exclusively either gay or straight and that those two binary classifications were too limiting.
C) He believed that people would lie to him and would need to be tricked into revealing that they were gay.
D) He thought that there would be a large number of transgender people in his sample.