Tributaries are streams or smaller rivers that meet a larger stream or river and helps in increasing its water volume. Bhima and Tungabhadra are major tributaries of the second-largest east-flowing Peninsular river. It is a river of south-central India and has a total length of about 1,400 km. Complete answer: Now let us look into the given options: Option A.) Ganga: The Ganges (Ganga) River originates as Bhagirathi from the ‘Gangotri glacier' in Uttarkashi District of Uttarakhand at an elevation of 7,010 m, and empties out into the Bay of Bengal. The river has a total length of about 2,500 km. The tributaries on its left bank are Ramganga, Gomti, Ghaghara, Gandak, Kosi and Mahananda, while its right bank tributaries are Yamuna, Tamsa, Son and Punpun. Thus, it is not the correct option. Option B) Krishna: It is a river in south-central India. It has a total length of about 1,400 km and is the second-largest east-flowing Peninsular river. The river rises at 'Mahabaleshwar' in district Satara of Maharashtra and meets the Bay of Bengal at Hamsaladeevi in Andhra Pradesh, on the east coast. The two largest tributaries of the river are Bhima (North) and Tungabhadra (South). Bhima emerges from the Matheron Hills and later meets the river Krishna near Raichur after a distance of 861 km. Tungabhadra is formed by the merging of the Tunga and the Bhadra arising from Gangamoola in the Central Sahyadri. Thus, it is the correct option. Option C) Godavari: Also known as ‘Dakshin Ganga’, it is the largest river system of Peninsular India with a total length of about 1,465 km. The river has its origin at ‘Trimbakeshwar’ in the Nashik district of Maharashtra at an elevation of 1,067 m. Its right bank tributaries are lesser in number and smaller in size than the left bank tributaries. Some of its left bank tributaries are Dharna, Penganga, Wainganga, Wardha, etc., While some of its right bank tributaries are Pravara, Mula, Manjra, Peddavagu, Maner etc. Thus, it is not the correct option. Option D) Mahanadi: The Mahanadi (“Great River”) has a total course of 900 km. This river originates in the northern foothills of ‘Dandakaranya' in Raipur District of Chhattisgarh, which is situated at an elevation of 442 m. Its upper course lies in the ‘Chhattisgarh Plain’, which is surrounded by hills on the north, west and south because of which various tributaries join the main river from these sides. The left bank tributaries of the river are- Seonath, Hasdeo, Mand and Ib, while its right bank tributaries are- Ong, Tel and Jonk. Thus, it is not the correct option. Thus, the correct answer is Option B i.e, Krishna. Bhima and Krishna are major tributaries of the river Krishna. Note: Students often get confused between some basic terminologies such as Confluence, Tributary and Distributary of a river. - The point at which two rivers or streams join is referred to as a ‘confluence'. - ‘Distributaries' are the small rivers that split from the main river and then never meet again. It thus reduces the river’s water volume. - ‘Tributary’ is a stream or smaller river which joins a larger stream or river and thus helps to increase its water volume.