Okay, let's tackle this question. The question is asking about the term for an active search for disease in someone who seems healthy. Hmm, I remember there are different levels of prevention in public health. Primary prevention is about preventing the disease before it occurs, like vaccinations. Secondary prevention is early detection and treatment, which might involve screening. Tertiary prevention is managing existing disease to prevent complications.

Wait, the options aren't provided, but the correct answer is supposed to be one of them. The term "screening" comes to mind here. Screening tests are used to detect diseases in asymptomatic individuals. For example, mammograms for breast cancer or PSA tests for prostate cancer. So the active search for disease in a healthy person would be screening. Let me confirm: screening is part of secondary prevention, aiming to catch diseases at an early stage when treatment is more effective.

The other options might be things like surveillance, which is ongoing monitoring. Or maybe case finding, but I think that's similar to screening. Diagnosis is when you determine the disease in someone who already has symptoms. So if the options include screening, that's the right answer. The incorrect options would be terms that are related but not exactly the same. Need to make sure the explanation is clear and covers why screening is correct and others are not.

**Core Concept**
The question tests understanding of public health terminology, specifically the distinction between *screening* and other preventive measures. Active disease detection in asymptomatic individuals falls under secondary prevention, focusing on early detection.

**Why the Correct Answer is Right**
**Screening** involves systematic testing of asymptomatic individuals to identify diseases at an early, preclinical stage. It aims to reduce morbidity and mortality by enabling timely intervention. Examples include mammography for breast cancer or Pap smears for cervical cancer. This differs from *surveillance* (ongoing monitoring) or *diagnosis* (assessment of symptomatic patients).

**Why Each Wrong Option is Incorrect**
**Option A:** *Surveillance* refers to continuous monitoring of populations or individuals at risk, not active case detection in healthy people.
**Option B:** *Case finding* is a broader term but often implies reactive identification in symptomatic populations, not proactive screening.
**Option C:** *Diagnosis* is the process of identifying a disease in a symptomatic patient, which does not align with the question’s focus on healthy individuals.

**Clinical Pearl / High-Yield Fact**
Remember: **"Screening saves lives"** by catching diseases early. NEET/USMLE often confuse "screening" with "surveillance"—screening is *proactive* (e.g., PSA tests), while surveillance is *reactive* (e.g., monitoring diabetics for retinopathy).

**Correct Answer: C. Screening**

✓ Correct Answer: C. Screening