The correct answer is: a) Oil India Limited (OIL).
Oil India Limited (OIL) is a government-owned oil and natural gas company in India. It was founded in 1959 and is headquartered in Duliajan, Assam. OIL is the largest producer of natural gas in India and the second-largest producer of crude oil. The company has operations in Assam, Arunachal Pradesh, Nagaland, Meghalaya, and Tripura.
Coal India Limited (CIL) is a government-owned coal mining company in India. It was founded in 1975 and is headquartered in Kolkata. CIL is the world’s largest coal producer by volume. The company has operations in 24 states of India.
The Geological Survey of India (GSI) is a government-owned geological survey organization in India. It was founded in 1851 and is headquartered in Kolkata. GSI is responsible for conducting geological surveys and mapping of India.
The Assam Mineral Development Corporation (AMDC) is a government-owned mineral exploration and mining company in Assam. It was founded in 1973 and is headquartered in Guwahati. AMDC is responsible for the exploration and mining of minerals in Assam.