According to the article, what was one problem caused by the fact that some people think vultures are ugly and disgusting?
A. Scientists have to work hard to convince people that medicines made from vulture parts actually work.
B. Conservationists have to work hard to convince the public to care about endangered vulture species.
C. Scientists have been hesitant to spend much time studying various vulture species.
D. Conservationists have been hesitant to spend money setting up a vulture conservancy