Wave Optics question for NEET / JEE Main, with solution

Answer: (C) increasing the diameter of the objective

Concept. Resolving power of a telescope $\propto \dfrac{D}{1.22\lambda}$.

Step 1. Apply. A larger objective diameter (or shorter wavelength) increases it.

Answer. Increasing the diameter of the objective (Option C).

Solution by Sreeraj P, M.Sc Physics