The question refers to “the following reaction sequence” and asks for the major product $Q$, but the actual reaction scheme/structures and the option structures (A–D) are missing from the prompt.

So, the problem is incomplete: without the starting compound, reagents, intermediates, or the structures of options A, B, C, and D, the major product cannot be determined logically.

What is needed to solve it

To identify $Q$, I would need at least:

1. The starting reactant structure
2. The full reaction sequence / reagents / conditions
3. The structures of options A, B, C, D

Only then can I:

• track the transformations step-by-step,
• identify the major product,
• compare it with the stored answer.

Comparison with stored correct answer

The stored correct answer is D, but since the actual reaction sequence and options are absent, I cannot independently verify whether D is correct.

Hence, I must disagree with automatic acceptance of the stored answer due to insufficient information.