Vector-borne diseases involve transmission by living organisms like insects

Steps:

• Define a vector as a living carrier, such as a mosquito, that transmits pathogens between hosts.
• Review transmission modes: AIDS/HIV via fluids, cholera via contaminated water, malaria via mosquito bites, measles via air.
• Match the definition to options: only malaria fits vector transmission.
• Confirm by eliminating non-vector diseases.

Why C is correct:

• Malaria is transmitted by the Anopheles mosquito vector, per the definition of vector-borne diseases from epidemiology.

Why the others are wrong:

• A. AIDS/HIV spreads through direct contact with infected bodily fluids, not vectors.
• B. Cholera is waterborne, transmitted via fecal-oral route in contaminated water or food.
• D. Measles spreads through airborne respiratory droplets, not vectors.

Final answer: C