Which of the following is responsible for depletion of ozone layer...

Nitric oxide ($\text{NO}$) is responsible for the depletion of the ozone layer in the stratosphere.

It is emitted from the exhaust systems of supersonic jet aeroplanes and reacts with ozone to form nitrogen dioxide and oxygen.

The reaction is given by:

$\text{NO}(g) + \text{O}_3(g) \rightarrow \text{NO}_2(g) + \text{O}_2(g)$

Thus, $\text{NO}$ acts as a catalyst in the depletion of ozone.

Answer: $\text{NO}$