The question statement is incomplete: it says, “The major products A and B in the following set of reactions are:” but the actual reaction scheme and the option structures are missing.

Because of that, it is not possible to determine the products uniquely.

What is missing

To solve this organic chemistry question, I would need:

1. The starting compound(s)
2. The reagents/conditions in each step
3. The structures of options A, B, C, D

Without these, no valid chemical deduction can be made.

Conclusion

Since the reaction sequence and answer choices are absent, I cannot derive the products or verify whether option B is correct based on chemistry.

Please provide the complete reaction diagram and the option structures, and I can solve it step-by-step.