## **Core Concept**
Malaria is a mosquito-borne infectious disease affecting humans and other animals. It is caused by parasitic protozoa of the genus *Plasmodium*. The transmission of malaria to humans occurs through the bite of infected female *Anopheles* mosquitoes.

## **Why the Correct Answer is Right**
The correct answer involves identifying the primary vectors of malaria. *Anopheles stephensi* and *Anopheles culicifacies* are both known vectors of malaria in different regions. *Anopheles stephensi* is commonly found in urban areas and is a major vector in cities, while *Anopheles culicifacies* is more prevalent in rural areas and is a significant vector in agricultural settings. Both species are implicated in the transmission of malaria.

## **Why Each Wrong Option is Incorrect**
* **Option C:** *Culex* mosquitoes are vectors of other diseases, such as filariasis and Japanese encephalitis, but not malaria.
* **Option D:** *Phlebotomus* is a genus of sandflies that transmit diseases like leishmaniasis, not malaria.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that not all *Anopheles* species transmit malaria; only about 30-40 species out of over 400 are actual vectors. *Anopheles stephensi* and *Anopheles culicifacies* are among the most important vectors in India.

## **Correct Answer:** B.