The Tungabhadra River is a major tributary of the:

Godavari
Krishna
Cauvery
Mahanadi

The correct answer is: b) Krishna.

The Tungabhadra River is a major tributary of the Krishna River. It originates in the Western Ghats of Karnataka and flows through the states of Karnataka and Andhra Pradesh before joining the Krishna River near Vijayawada. The Tungabhadra River is a major source of irrigation and hydroelectric power for the region. It is also a popular tourist destination, with many temples and historical sites located along its banks.

The Godavari River is the longest river in India. It originates in the Western Ghats of Maharashtra and flows through the states of Maharashtra, Telangana, Andhra Pradesh, and Odisha before emptying into the Bay of Bengal. The Godavari River is a major source of irrigation and hydroelectric power for the region. It is also a popular tourist destination, with many temples and historical sites located along its banks.

The Cauvery River is the second longest river in India. It originates in the Western Ghats of Karnataka and flows through the states of Karnataka, Tamil Nadu, and Kerala before emptying into the Bay of Bengal. The Cauvery River is a major source of irrigation and hydroelectric power for the region. It is also a popular tourist destination, with many temples and historical sites located along its banks.

The Mahanadi River is the longest river in the Indian state of Odisha. It originates in the Eastern Ghats of Odisha and flows through the states of Odisha, Chhattisgarh, and Jharkhand before emptying into the Bay of Bengal. The Mahanadi River is a major source of irrigation and hydroelectric power for the region. It is also a popular tourist destination, with many temples and historical sites located along its banks.