Answer:
a. all can be transmitted through contact with the rash/lesion
Step-by-step explanation:
All the three diseases i.e. chickenpox, smallpox, and syphilis can be transmitted through contact with the rash/lesion.
Chicken pox: Chickenpox is a viral infection in which red blisters appear on the skin. It is caused by Varicella-zoster virus.
Smallpox: Smallpox was certified the global eradication by WHO in the year of 1980. Smallpox is a viral infection caused by the Variola virus. Variola viruses are of two types named Variola major and Variola minor.
Syphilis: Syphilis is a bacterial disease which is the most dangerous infection spread through sexual contact.