In the U.S. ______ percent of the infants with AIDS are white.

A．all HIV carriers are doomed to die
B．only those who show clinical evidence of AIDS will pass on the virus
C．the number of AIDS cases will be reduced in the 1990s
D．IV drug users are a high-risk group vulnerable to AIDS infection

A．People engaged in the business of entertainment.
B．Homosexual and bisexual men.
C．Intravenous drug users.
D．Poor urban residents.