The Primary Health Centre (PHC) is the basic structural and functional unit of the public health services in developing countries. PHCs were established to provide accessible, affordable and available primary health care to people, in accordance with the Alma Ata Declaration of 1978 by the member nations of the World Health Organisation WHO.

The correct answer is option 'B' - Primary Healthcare Centres (PHC).

Primary Healthcare Centres (PHCs) are an essential component of the healthcare system, particularly in developing countries. These centers play a crucial role in providing basic healthcare services to the population residing in rural and remote areas.

Below is a detailed explanation of the answer:

1. Definition and Purpose:
- Primary Healthcare Centres (PHCs) are the first point of contact for individuals seeking healthcare services.
- They are designed to provide comprehensive, accessible, and affordable healthcare to individuals and communities.
- The primary purpose of PHCs is to deliver essential healthcare services, including preventive, promotive, curative, and rehabilitative care.

2. Services Offered:
- PHCs offer a wide range of healthcare services, which include immunizations, maternal and child healthcare, family planning, treatment of common ailments, health education, and preventive measures.
- These centers are equipped to handle minor surgeries, emergency care, diagnostic services, and referrals to higher-level healthcare facilities when needed.
- PHCs also focus on disease prevention and health promotion through community-level interventions.

3. Location and Coverage:
- PHCs are typically established in rural and remote areas where access to healthcare services is limited.
- They aim to bridge the gap between urban and rural healthcare facilities, ensuring equitable healthcare for all.
- The coverage area of a PHC depends on factors like population density, geographical terrain, and healthcare needs of the community.

4. Manpower and Infrastructure:
- PHCs are staffed with a team of healthcare professionals, including doctors, nurses, pharmacists, and support staff.
- The infrastructure of a PHC usually includes outpatient departments, inpatient facilities, laboratory services, pharmacy, and ambulance services.
- These centers are often equipped with essential medical equipment and medicines to cater to the healthcare needs of the community.

5. Importance and Impact:
- PHCs are vital for achieving universal healthcare coverage and addressing health inequities.
- They play a crucial role in early detection and management of diseases, reducing the burden on secondary and tertiary healthcare facilities.
- PHCs contribute to community empowerment, health education, and capacity building, leading to improved health outcomes and a healthier population.

In conclusion, Primary Healthcare Centres (PHCs) are the backbone of the healthcare system, providing essential healthcare services to individuals and communities. They serve as the first point of contact for healthcare needs and play a vital role in promoting health, preventing diseases, and reducing health inequalities.