**Core Concept**
Malaria surveillance involves monitoring the incidence of malaria cases in a population to guide public health interventions. Active surveillance involves actively searching for cases rather than relying on passive reporting. At the Primary Health Center (PHC) level, data collection is crucial for effective malaria control.

**Why the Correct Answer is Right**
The correct answer is responsible for data collection through active surveillance, which includes house-to-house searches, door-to-door surveys, and other methods to identify cases. This involves identifying individuals with fever or other symptoms suggestive of malaria and collecting blood samples for laboratory confirmation. The data collected is then used to calculate incidence rates, identify high-risk areas, and guide targeted interventions.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not have a direct role in data collection for active malaria surveillance at the PHC level.
**Option B:** This option is incorrect because it is responsible for treatment and management of malaria cases, not data collection.
**Option C:** This option is incorrect because it is responsible for laboratory confirmation of malaria cases, not data collection.

**Clinical Pearl / High-Yield Fact**
The World Health Organization recommends active surveillance as a key strategy for malaria control, particularly in areas with high transmission rates. This involves not only data collection but also prompt treatment and follow-up of cases to prevent complications and reduce transmission.

**Correct Answer: C. ASHA (Accredited Social Health Activist)**