Identify A and B in above reaction.

The starting material is a cyclohexene derivative with a methoxy group ($-\text{OCH}_3$) at C1, a double bond between C2 and C3, and a nitro group ($-\text{NO}_2$) at C4.

In the first step, electrophilic addition of $\text{HCl}$ to the double bond occurs. Protonation of the $\text{C2}=\text{C3}$ double bond can form a carbocation at either C2 or C3.
A carbocation at C3 is adjacent to the $-\text{NO}_2$ group, which is strongly electron-withdrawing via its $-I$ effect, making this intermediate highly unstable.
A carbocation at C2 is adjacent to the $-\text{OCH}_3$ group. Although $-\text{OCH}_3$ also exerts a $-I$ effect, it is significantly weaker than that of $-\text{NO}_2$. Thus, the intermediate carbocation predominantly forms at C2.

The chloride ion ($\text{Cl}^{-}$) then attacks the more stable carbocation at C2. Therefore, the major product [A] is the 2-chloro isomer.

In the second step, [A] reacts with $\text{NaI}$ in dry acetone. This is a standard Finkelstein reaction, which proceeds via an $S_N2$ mechanism to substitute the chlorine atom with an iodine atom.
The replacement occurs at the same carbon (C2), yielding the 2-iodo isomer as the major product [B].

Comparing this with the given options, Option (1) correctly shows [A] with the $-\text{Cl}$ group at C2 and [B] with the $-\text{I}$ group at C2.

Answer: