We Have Little Reliable Data on Human Sexuality Because

We have little reliable data on human sexuality because

A) it is difficult for researchers to even broach the subject.
B) until the AIDS crisis,there was little scientific demand for data on sexual behavior.
C) government funding for studies of sexual behavior is easily accessible,but not many want to ask for it.
D) there has been an increase in the use of inaccurate data over the last decade.