The question as provided is incomplete.

1. The prompt says:

   • “The structures of major products $A$, $B$ and $C$ in the following reaction are sequence.”
   • But the actual reaction scheme and the option structures are missing.

2. Since the reaction sequence is not shown, it is impossible to determine:

   • what compound forms product $A$,
   • how $A$ converts to $B$,
   • how $B$ converts to $C$,
   • and which option matches the correct sequence.

3. Therefore, a genuine chemistry solution cannot be derived from the supplied data alone.

4. The stored correct answer is given as A, but without the reaction and option diagrams, this cannot be independently verified.

5. To solve this properly, please provide either:

   • the full reaction image/scheme, or
   • the reactant, reagents, and all option structures in text form.

Hence, no valid step-by-step chemical derivation is possible from the current information.