Answer:
The Structure of "B" is alkene.
Explanation:
The compound "A" having R- configuration and undergoes Hofmann elimination to form an alkene.
The compound "B" on oxidatively cleaving with ozone followed by dimethyl sulfide forms [tex]CH_{2}=S[/tex] and [tex]CH_{3}CH_{2}CH_{2}CHO[/tex]
The structure of "A" and"B" is as follows.