What do you understand by the term "Ozone depletion"?

Reduction in the amount of ozone  Increase in the density of ozone layer Decrease in CFC's in the stratosphere Both 1 and 3

Reduction in the amount of ozone

When the amount of ozone decreases in the stratosphere it is called as "Ozone depletion". It is caused by high levels of bromine and chlorine compounds in the stratosphere.