Chlorine radical (\( \cdot \text{Cl} \)) is well-known to play a significant role in the depletion of ozone in the stratosphere. The chlorine radicals catalytically break down ozone molecules (\( \text{O}_3 \)) into oxygen molecules (\( \text{O}_2 \)) and oxygen atoms (\( \text{O} \)), leading to a reduction in the ozone layer.
Thus, \( \cdot \text{Cl} \) is the correct radical responsible for ozone depletion.