Explanation:

Introduction:
India is one of the largest consumers of petroleum and petroleum products in the world. To meet the increasing demand for petroleum, India has focused on increasing its domestic production. In this context, the question asks about the percentage of India's petroleum production that comes from different regions.

Assam:
Assam is one of the major petroleum-producing states in India. It is known for its oil fields such as Digboi, Naharkatiya, and Moran. However, Assam's contribution to India's petroleum production is not as significant as other regions. Therefore, option 'a' is not the correct answer.

Mumbai High:
Mumbai High, also known as the Bombay High, is an offshore oil field in the Arabian Sea. It is located approximately 160 kilometers west of the coast of Mumbai. Mumbai High is one of the largest oil fields in India and has been a significant contributor to India's petroleum production. Therefore, option 'b' is the correct answer.

Gujarat:
Gujarat is another important region for petroleum production in India. It is known for its oil fields such as Ankleshwar, Kalol, and Mehsana. Gujarat has a significant share in India's petroleum production. However, it is not the largest contributor. Therefore, option 'c' is not the correct answer.

Conclusion:
Based on the information provided, the correct answer is option 'B' - Mumbai High. Mumbai High contributes about 63 percent of India's petroleum production. It is a major offshore oil field located in the Arabian Sea, west of the coast of Mumbai.