Which one of the following river basins is the largest in respect to area?

1. A

   Tapti

   Option (a) claims that the Tapti river basin is the largest in area among the given options. However, the drainage area of the Tapti river is smaller than that of the Mahanadi, making this option incorrect.

2. B

   Narmada

   Option (b) asserts that the Narmada river basin covers the maximum area among the listed rivers. While Narmada is a major west-flowing peninsular river, its total catchment area is smaller than the Mahanadi river basin, thus ruling out this choice.

3. C

   Mahanadi

   Option (c) states that the Mahanadi river basin is the largest in respect to area among the choices provided. Spanning across states like Chhattisgarh and Odisha, the Mahanadi possesses a significantly larger drainage basin area than Tapti, Narmada, and Cauvery, thereby making this option the correct official key.

4. D

   Cauvery

   Option (d) holds that the Cauvery river basin is the largest in area. Situated in the southern part of India, the Cauvery basin has a relatively smaller geographical area compared to the Mahanadi basin, rendering this option wrong.

Summary. Official key is (c) in respect to the largest river basin among the given choices. The Mahanadi river drains a vast area of approximately 141,600 square kilometres, surpassing the basins of the Tapti, Narmada, and Cauvery rivers. Aspirants often confuse the peninsular river lengths and discharge capacities with total catchment basin areas. Careful comparison of the geographical drainage extents reveals that Mahanadi occupies the top position here. Therefore, option (c) is accurately established as the correct answer based on hydrological data.