Answer:
A) Dengue Fever
Step-by-step explanation:
The Dengue virus is transmitted by mosquitos in tropic and sub-tropic regions.
Lyme disease is spread by ticks, HIV/AIDS is a STD, cancer isn't spread by mosquitos, and malaria is technically spread by mosquitos BUT it's due to a parasite carried by the mosquito and Malaria is common in South Asia and sub-Saharan African regions no subtropic regions. The answer is Dengue Fever.