Suppose a volcanic eruption included large volumes of chlorine. what would likely happen to global stratospheric ozone levels and why?

Suppose a volcanic eruption included large volumes of chlorine. In that time Ozone levels would decrease in the stratospheric because chlorine interferes with the O3:UV:O2+O cycle. The ozone–oxygen cycle is the process by which ozone is continually regenerated in Earth's stratosphere, converting ultraviolet radiation (UV) into heat.

This is the answer: body 1 + engine 2