Which form of $UV-$radiation is allowed to pass through ozone and reach the earth surface?

The Montreal Protocol aims at:

The reduction in the emission of global ozone-depleting substances was accepted by which of the following protocols?

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.

When and where was the ozone hole discovered?

The ozone layer in the upper atmosphere $(stratosphere)$ is destroyed by which of the following chemicals, or which chemical is responsible for the reduction of the ozone content of the atmosphere?