What is the correct order of reactivity of the following compounds in nucleophilic

Explanation:

The structures differ only at the point of halogen,so considering them it can further elaborated as follows:

In group 17, when we move down the group (F → Cl → Br → I), reactivity for nucleophilic substitution (S_N) decreases because when the given compounds are treated with NaOH, acid-base reaction takes place, NaOH extracts a H⁺ ion from the ring resulting in negative charge over the ring.

Now, if the -ve charge is well-distributed over the ring, then the intermediate would be stable, making the reaction more feasible.

So, to distribute the negative charge, - I (induction effect) of the substituent comes into play. Since order of -I is F>Cl>Br>I

So order of stability of intermediate (-ve charge distribution) would be I>II>III>IV.

Final Answer:

Hence, the correct answer is option A.:  I>II>III>IV.