Assertion (A): The rainbow is a natural spectrum of sunlight in the sky. Reason (R): Rainbow is formed in the sky when the sun is overhead and water droplets are also present in air.

Assertion (A) is true as a rainbow is indeed a natural spectrum produced by the dispersion of sunlight by raindrops. Reason (R) is false because a rainbow is always formed in a direction opposite to that of the Sun. If the Sun is directly overhead, the geometry required for the internal reflection and dispersion of light to reach the observer's eye on the ground is generally not met; therefore, rainbows are typically seen in the morning or evening when the sun is at a lower angle.