Which two roads subtend $120°$ at the center i.e., at India Gate?

Given:
Map of India Gate

To find:
Two paths that subtend $120°$ at the center.

Calculation:

1. Place the protractor with its center at India Gate.
2. Adjust the protractor such that $0°$ line coincides with Dr. Zakir Hussain Marg.
3. Observe which road coincides with the $120°$ on the protractor.

It can be seen that Tilak Marg and Dr. Zakir Hussain Marg subtend $120°$ at the center.

Hence, the correct answer is option B.