Correct Answer: (a) Ganga, Godavari, Krishna, Yamuna
Solution:The correct sequence of river lengths in decreasing order is:
Ganga, Godavari, Krishna, Yamuna
The length of Ganga is 2525 km, Godavari is 1465 km, and Krishna is 1400 km, Yamuna is approxi- mately 1376 km. So, the correct answer is option (a).