**Core Concept**
The question is testing the knowledge of the most effective medium for mass education of the general public, which is a crucial aspect of public health education and disease prevention.

**Why the Correct Answer is Right**
The correct answer is television, as it is widely available, easily accessible, and can reach a large audience simultaneously. According to various studies, television is considered the most effective medium for mass education due to its ability to convey complex information in a simple and engaging manner, making it easy for the general public to understand and retain.

**Why Each Wrong Option is Incorrect**
**Option A:** Radio is not considered the most effective medium for mass education, as it is limited by its auditory nature and cannot convey complex visual information.

**Option B:** Newspapers are not as effective as television in mass education, as they are limited by their print format and may not be accessible to a large audience.

**Option C:** Social media is not the most effective medium for mass education, as it is often fragmented and may not reach a broad audience, despite its potential for targeted advertising.

**Clinical Pearl / High-Yield Fact**
It's essential to note that public health education is a critical component of disease prevention and control, and the choice of medium is crucial in effectively conveying health information to the general public.

**Correct Answer: D. Television**