Since 1985, There Have Been Many More Reported Cases of Genital

Since 1985, there have been many more reported cases of genital chlamydia in the United States. Doctors think this increase is most likely due to

A) a new epidemic, similar to AIDS in the 1980s.
B) mutation to a more virulent strain.
C) increased recognition and diagnosis of an existing condition.
D) a significant increase in unprotected sex among young people.
E) a recent flare-up of cases that had been latent for several decades.