In the question given below there are 2 statements marked as Assertion (A) and Reason (R). Choose the correct alternative from the following options.

Assertion (A)- Ozone depletion refers to the phenomenon of reductions in the amount of ozone in the troposphere

Reason (R)- The major reason behind the depletion of ozone layer is use of CFC's in AC, fridge etc.

(A) Is false but (R) is true.

The correct answer is Option 4: (A) Is false but (R) is true.

Explanation:

• Assertion (A): "Ozone depletion refers to the phenomenon of reductions in the amount of ozone in the troposphere." This is false. Ozone depletion specifically refers to the reduction of ozone in the stratosphere, not the troposphere. The stratospheric ozone layer is crucial for blocking harmful UV radiation.

• Reason (R): "The major reason behind the depletion of ozone layer is use of CFC's in AC, fridge etc." This is true. Chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS) are significant contributors to the depletion of the ozone layer in the stratosphere.

Thus, while the reason about CFCs is correct, the assertion about ozone depletion affecting the troposphere is incorrect.