What does the term 'ozone hole' refer to?

Given below are two statements.
Statement $I$: Absorption of $UV$ radiations is directly proportional to the thickness of ozone.
Statement $II$: Ozone is generated by absorption of shorter wavelength of infrared radiations.
In the light of the above two statements,choose the correct answer from the options given below.

World Ozone Day is celebrated on

Assertion : $UV$ radiation causes photodissociation of ozone into $O_2$ and $O$,thus causing damage to the stratospheric ozone layer.
Reason : Ozone hole is resulting in global warming and climate change

The zone of the atmosphere in which the ozone layer is present is called:

Which of the following absorbs ultraviolet radiation from the sun?