Answer:
The correct answer would be c. destroy ozone in the stratosphere.
CFC's (chlorofluorocarbons) and halon are the man-made chemicals which are the major contributors in the destruction or thinning of the ozone layer in the stratosphere.
These chemicals can get away into the upper atmosphere where ultraviolet rays or solar radiations break them to release bromine and chlorine atoms in the atmosphere.
These atoms react with the ozone molecules and break them apart to release oxygen.
The rate of this reaction is higher than that of natural replenishment of ozone.
This leads to the depletion or thinning of the ozone.