**Core Concept**
The Primary Health Centre (PHC) is a basic structural and functional unit of the public health services in developing countries, aiming to provide accessible, preventive, and curative healthcare to the community. **PHC staff** typically includes a mix of medical, paramedical, and support personnel. The composition of PHC staff is designed to meet the primary healthcare needs of the population.

**Why the Correct Answer is Right**
The correct answer includes personnel who are essential for the day-to-day functioning of a PHC, such as a **pharmacist** to manage medications, a **clerk** for administrative tasks, a **laboratory technician** for diagnostic tests, and sometimes a **paediatrician** for child healthcare. These roles are fundamental to providing primary care services.

**Why Each Wrong Option is Incorrect**
**Option C:** A **radiologist** is a specialist who interprets imaging studies and is not typically part of the basic staff at a PHC due to the specialized nature of their work and the equipment required.

**Clinical Pearl / High-Yield Fact**
Remember, the staff composition at a PHC is tailored to provide basic and essential healthcare services to the community, including preventive, curative, and rehabilitative care.

**Correct Answer:** D. Pharmacist, Clerkc, Laboratory technician, Paediatrician