Which method would work the best in accomplishing the following transformation?

Question

Quizplus · Accepted Answer

The given chemical structure contains a long and repetitive sequence of the same molecule. The best method to transform this structure would be to replace the H atoms with a Br functionality using Br₂. This can be achieved by choice B as it uses Br₂ as the first step and then adds 2eq. of NaNH₂ in the second step to remove the H atoms. Choice A only adds HBr, which does not result in the desired transformation, and choice C uses an unnecessary secondary transformation step to add an O atom. Choice D uses a more complex and lengthy transformation that is not required for this type of structure.

Which Method Would Work the Best in Accomplishing the Following