The correct option is D Syphilis
Syphilis is a bacterial disease caused by Treponema pallidum. It usually spreads by sexual contact. The disease starts as a painless sore, typically on your genitals, rectum or mouth.
Small pox is caused by two virus variants, Variola major and Variola minor.
Herpes is caused by herpes simplex virus.
AIDS is caused by Human Immunodeficiency Virus