Answer
(a)
Work Step by Step
The correct identification of i, ii, iii, and iv in the equations is as follows:
i + ii → iii
UV-C radiation + $O_2$ → $2O$
so
i = UV-C radiation
ii = $O_2$
iii + CFC → iv + $O_2$
$O_3$+CFC → ClO+$O_2$
iii = $O_3$
iv = ClO
The answer is (a).
