The correct option is B Both (A) and (R) are true but (R) is not the correct explanation of (A).
In May and June, the Sun rays fall vertically over the Equator and India. Since India, especially Tamil Nadu is closer to the Equator, the summers are very harsh in Tamil Nadu. During January and February, the Northern Hemisphere faces away from the Sun. The rays of the Sun fall between Tropic of Capricorn and the Equator and India receive slant rays from the Sun. Due to this, India experiences winter.