Given below are two statements, one is labelled as Assertion (A) and other as Reason (R):

Assertion (A) : Teesta river was earlier a tributary of Ganga now it is a tributary of Brahmaputra.
Reason (R) : River capturing is a major feature of Himalayan rivers.

Select the correct answer using the codes given below.
Codes :

Explanation

Teesta River rises in the Pauhunri Mountain of eastern Himalayas, flows through the Indian states of Sikkim and West Bengal through Bangladesh and enters the Bay of Bengal.

It joins Brahmaputra River at Phulchhari Upazila in Bangladesh. 305 km portion of the river lies in India and rest in Bangladesh.

Teesta is the largest river of Sikkim and second largest river of West Bengal after Ganges.

In Bangladesh, the Teesta joins the Brahmaputra on its right bank, from where the river is known as the Yamuna. Then, it finally merges with the river Padma, which falls in the Bay of Bengal.

Tista River is a tributary of the Jamuna River (Brahmaputra River).

Historically, the Teesta river system was considered the major tributary of the Ganges.