Question

Maximum ozone depletion is caused by
a) $CO_2$
b) CFC
c) $SO_2$
d) $CH_4$

Answer 1

Hint: The main cause of ozone depletion is manufactured chemicals, especially halocarbon refrigerants, solvents, propellants, and foam- blowing agents, which is referred to as ozone-depleting substances (ODS).

Complete answer:
Ozone is concentrated about 9 to 18 miles above the Earth's surface in the stratosphere. Ozone gas is made up of three oxygen atoms $(O_3)$. Ozone protects life on Earth from the ultraviolet (UV) radiation from the sun. Oxone filters the UV radiation from the sun so it doesn't reach Earth.

The ozone layer is depleting particularly over Antarctica and over the Arctic. The depletion is caused by the destruction of ozone by manufactured chemicals, especially halocarbon refrigerants, solvents, propellants, and foam- blowing agents, which is referred to as ozone-depleting substances (ODS). Among the ozone depleting substances, the maximum ozone depletion is caused by chlorofluorocarbons (CFCs) and halon gases formerly found in aerosol spray cans and refrigerants and are released into the atmosphere and destroy the ozone layer.

Hence, the correct answer is option (B).

Additional information:
The ozone hole of Antarctica is now recovering. In 2019 and 2020 the hole was the smallest on record but it will take many years for the chemicals like CFC to completely remove from the atmosphere.

Note: When chlorine atoms of CFC come into contact with ozone in the stratosphere, it destroys $O_3$ molecules by converting $O_3$ molecules into $O_2 + O$. One Cl atom can destroy almost 100,000 ozone molecules. So, ozone is destroying more quickly than it is naturally creating. So, a hole is formed in the ozone layer, called an ozone hole.