True I think but not sure
The correct option is C, THAT IS, OZONE.
CFC acts as catalyst, which enable oxygen to react rapidly with ozone, leading to the destruction of the ozone layers. The whole process is a series of free radical reactions that occur in five stages. A single molecule of CFC can destroy as much as 100,000 ozone molecules. Depletion of ozone layers has grave consequences such as skin cancers, eye damages, etc.
It's letter c i believe, because they need the DNA's instruction on how to copy the exact tissue copy.