Which Five Year Plan period saw the initiation of the Hill Area Development Programme?

The correct option is Fifth Five Year Plan.

Detailed Explanation:
The Hill Area Development Programme (HADP) was initiated during the Fifth Five Year Plan (1974–1979) in India.
This program was launched with the primary objective of addressing the socio-economic development of hilly areas, which were lagging behind due to difficult terrain, geographical isolation, and environmental challenges.

Key Objectives of the Hill Area Development Programme:
1. Ecological Preservation and Restoration: The foremost focus was to prevent ecological degradation and promote sustainable development in fragile hill ecosystems through forestry, soil conservation, and water management.
2. Socio-economic Upliftment: Promoting local livelihoods by developing horticulture, agriculture, animal husbandry, and village industries tailored to the hill environment.
3. Infrastructure Development: Enhancing basic infrastructure such as road connectivity, clean drinking water, education, and healthcare facilities to improve the quality of life for the inhabitants of these regions.

By targeting specific backward and hilly districts across states (such as Assam, West Bengal, Uttarakhand, and Tamil Nadu), the programme aimed to reduce regional imbalances and integrate these areas into the mainstream national developmental process.