One of the Main Reasons for an Increase in Gonorrhea

One of the main reasons for an increase in gonorrhea in the last couple of decades has been:

A) that gonorrhea has always increased during wartime activity.
B) that gonorrhea has mutated and is no longer curable with antibiotics.
C) the shift from the condom to the pill that has raised the infection among women.
D) the fact that both infected males and females are now asymptomatic for longer durations.