Answer:
Step-by-step explanation:
The problem is based on resolving power of instruments . Resolving power of instruments is related to wavelength of light as follows
resolving power of telescope ∝ 1 / λ
Higher the resolving power closer the object that can be looked separately.
Wave length of blue light is shorter than that of red light so resolving power in case of blue light will be higher. So we have better chance of distinguishing separate bulbs when color light is blue.