Question Type: General Knowledge/Geography

This question tests knowledge of Indian rivers and their drainage systems.

Step-by-step Solution:

• The Ganga River system is one of the largest river systems in India. Many rivers are tributaries of the Ganga, meaning they flow into the Ganga River.
• Gomti, Ghaghara, and Kosi are all tributaries of the Ganga River. They join the Ganga at different points along its course.
• The Mahanadi River, however, is not a tributary of the Ganga. It flows independently and directly empties into the Bay of Bengal.

Core Logic/Pattern: Identifying the correct tributary relationship of rivers in India. The correct option is the one that doesn't follow the pattern of being a tributary to the Ganga River.

Eliminating Incorrect Options:

• Gomti: A tributary of the Ganga.
• Ghaghara: A tributary of the Ganga.
• Kosi: A tributary of the Ganga.

Correct Answer: Mahanadi