Which are the compounds responsible for ozone layer depletion?

Which of the following synthetic chemicals is responsible for ozone layer depletion?

Name the chemical which is mainly responsible for ozone-layer depletion ?

Which of the following is mainly responsible for ozone depletion ?

What are the reactions involved for ozone layer depletion in the stratosphere?

The main reason of ozone layer depletion is :

State one important function of ozone layer in the atmosphere. How is it formed there? Which compounds are responsible for the depletion of ozone layer? How do these compounds enter into the atmosphere