The light energy escaping from the Sun can be spread by

The light energy escaping from the Sun can be spread by

a shower of rain drops
a plane mirror
a convex lens
a combination of a convex lens and a concave lens
This question was previously asked in
UPSC NDA-1 – 2019
The correct answer is A) a shower of rain drops.
This question is likely referring to the phenomenon of dispersion of light, where white sunlight is separated into its constituent colors. A shower of raindrops acts like a large number of tiny prisms. As sunlight enters a raindrop, it is refracted, dispersed into its spectral colors, reflected internally, and then refracted again upon exiting the raindrop. This process creates a rainbow, which is a visible spectrum of sunlight. A plane mirror reflects light but does not disperse it. A convex lens converges light, and while it can refract light, its primary function is focusing, not spreading or dispersing white light into a spectrum like a prism or raindrop does. A combination of lenses can be used for various optical purposes but typically not for simply spreading or dispersing sunlight into its spectrum in the manner suggested by the formation of a rainbow.
Dispersion is the phenomenon where the speed of light in a medium depends on its wavelength (or color). Different wavelengths are refracted at slightly different angles, causing the separation of white light into its spectrum. Prisms and diffraction gratings are commonly used to demonstrate dispersion. A rainbow is a natural example of dispersion by water droplets.