Assertion (A) The ozone layer present in the upper atmosphere of Earth is beneficial for sustaining life on the Earth. Reason (R) The ozone layer blocks the harmful ultraviolet rays from the Sun and thus proctects life on the Earth.

• if both A and R are true and R is the correct explanation of A
• if both A and R are true and R is not the correct explanation of A
• if A is true but R is false
• if A is false but R is true