In the List-I, four optical effects are mentioned. The physical phenomena of light which are essential to describe these optical effects are given in List-II. Choose the option which describes the correct match between the entries in List-I to those in List-II.

List-I	List-II
(P) Colorful sky in north polar region (Aurora Borealis)	(1) Dispersion and reflection
(Q) Partially polarized sunlight	(2) Total internal reflection
(R) Rainbow	(3) Diffraction
(S) Dark and bright fringes	(4) Scattering of light by molecules in the atmosphere
	(5) Emission of radiation from oxygen and nitrogen atoms excited by charged particles

The correct option is P → 5, Q → 4, R → 1, S → 3.

Let us analyze each optical effect given in List-I and match it with the corresponding physical phenomenon in List-II:

1. (P) Colorful sky in north polar region (Aurora Borealis):
Aurora Borealis occurs when energetic charged particles (such as electrons and protons) from the solar wind collide with oxygen and nitrogen atoms in Earth's upper atmosphere. These collisions excite the gas atoms, which subsequently release light energy upon returning to their ground states.
Thus, P matches with (5): Emission of radiation from oxygen and nitrogen atoms excited by charged particles.

2. (Q) Partially polarized sunlight:
Unpolarized sunlight entering Earth's atmosphere undergoes Rayleigh scattering by air molecules. Light scattered at angles other than 90° becomes partially polarized, while light scattered at exactly 90° to the incident direction is strongly linearly polarized.
Thus, Q matches with (4): Scattering of light by molecules in the atmosphere.

3. (R) Rainbow:
A rainbow is formed due to the dispersion of sunlight as it enters atmospheric water droplets, followed by internal reflection (or total internal reflection in droplets) and refraction back into the observer's line of sight.
Thus, R matches with (1): Dispersion and reflection.

4. (S) Dark and bright fringes:
Dark and bright fringes are characteristic patterns produced when light waves encounter an obstacle, opening, or slit and undergo diffraction (as well as interference).
Thus, S matches with (3): Diffraction.

Combining all the correct matches gives:
P → 5, Q → 4, R → 1, S → 3