Assertion (A): A black body is an ideal body that emits and absorbs radiation of all frequencies.
Reason (R): The frequency of radiation emitted by a body goes from lower frequency to a higher frequency with an increase in temperature.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.

Hint: With the temperature intensity of light increases.
A body that absorbs and emits all radiations falling on it is called a perfect black body. With rise in temperature, the frequency of radiation emitted by the body increases.