The major river flowing through Bihar is:

Brahmaputra
Ganga (Ganges)
Yamuna
Godavari

The correct answer is: b) Ganga (Ganges).

The Ganga is the longest river in India and the third longest river in Asia. It flows through the states of Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, West Bengal, and the union territory of Delhi. The Ganga is a sacred river for Hindus and is considered to be the source of life. It is also an important source of water for irrigation and drinking water.

The Brahmaputra is the second longest river in India and the ninth longest river in Asia. It flows through the states of Arunachal Pradesh, Assam, and Meghalaya. The Brahmaputra is a major source of water for irrigation and drinking water. It is also an important river for transportation.

The Yamuna is the longest tributary of the Ganges. It flows through the states of Uttarakhand, Uttar Pradesh, Haryana, and Delhi. The Yamuna is a major source of water for irrigation and drinking water. It is also an important river for transportation.

The Godavari is the longest river in the Deccan Plateau. It flows through the states of Maharashtra, Telangana, Andhra Pradesh, Karnataka, and Madhya Pradesh. The Godavari is a major source of water for irrigation and drinking water. It is also an important river for transportation.