The question refers to a reaction sequence and asks for product B, but the actual reaction scheme/image and the structures of options A, B, C, D are missing from the prompt.

So, as given, the problem is incomplete, and product $B$ cannot be determined from the text alone.

Step 1: What is missing?

To solve such an organic chemistry question, we need:

1. The starting compound
2. The reagents/conditions in each step of the sequence
3. The structures corresponding to options A, B, C, and D

None of these are present in the prompt.

Step 2: Can the stored answer be verified?

The stored correct answer is given as D, but without the reaction sequence and option structures, there is no chemical basis to verify whether D is actually correct.

Conclusion

The question is not solvable in its current form because the essential reaction information is absent.

Please provide the reaction sequence diagram/image and the option structures, and I can then solve it step-by-step and verify whether option D is correct.