Step 1: Evaluate the assertion.
Malaria is controlled by preventing the transmission of Plasmodium, mainly through control or eradication of mosquito vectors.
Thus,
\[
\boxed{\text{Assertion (A) is true}.}
\]
Step 2: Evaluate the reason.
The infective stage (sporozoites) is transmitted to humans through the bite of an infected female Anopheles mosquito.
Therefore,
\[
\boxed{\text{Reason (R) is true}.}
\]
Step 3: Relate the assertion and reason.
Since malaria spreads through female Anopheles mosquitoes, controlling these vectors helps control the disease.
Hence,
\[
\boxed{\text{(R) correctly explains (A).}}
\]
Therefore,
\[
\boxed{(A)}
\]
is the correct answer.