What is stratospheric `O_3` layer?

Freon gas causing stratospheric O_(3) depletion is mainly released from :

Assertion (A) : Presently, the global atmosphere is warming up. Reason (R): The depletion of stratospheric ozone layer has resulted in increase in ultraviolet radiations reaching the Earth.

Natural sink of stratospheric ozone layer is :

Consider the following statements: 1. Ozone is found mostly in the Stratosphere 2. Ozone layer lies 55-75 km above the surface of the earth -3. Ozone absorbs ultraviolet radiation from the Sun 4. Ozone layer has no significance for life on the earth Which of the above statements are correct?

Consider the following statements : 1. Ozone is mostly found in the stratosphere. 2. Ozone layer lies 55-75 km above the surface of the Earth. 3. Ozóne absorbs ultraviolet radiation from the Sun.' 4. Ozone layer has no significance for life on the Earth. Which of the statements given above are correct?