Formation of photochemical smog involves the following reaction in which A, B and C are respectively.
(i) NO$$_2$$ $$\xrightarrow{h\nu}$$ A + B
(ii) B + O$$_2$$ $$\to$$ C
(iii) A + C $$\to$$ NO$$_2$$ + O$$_2$$
Choose the correct answer from the options below:

We need to identify A, B, and C in the photochemical smog reactions.

Reaction (i): $$\text{NO}_2 \xrightarrow{h\nu} \text{A} + \text{B}$$

When NO$$_2$$ absorbs UV radiation, it undergoes photodissociation:

$$\text{NO}_2 \xrightarrow{h\nu} \text{NO} + \text{O}$$

So $$A = \text{NO}$$ and $$B = \text{O}$$ (atomic oxygen).

Reaction (ii): $$\text{B} + \text{O}_2 \to \text{C}$$

$$\text{O} + \text{O}_2 \to \text{O}_3$$

So $$C = \text{O}_3$$ (ozone).

Reaction (iii): $$\text{A} + \text{C} \to \text{NO}_2 + \text{O}_2$$

$$\text{NO} + \text{O}_3 \to \text{NO}_2 + \text{O}_2$$ ✓

Therefore, A = NO, B = O, C = O$$_3$$.

The correct answer is Option 4: NO, O and O$$_3$$.