Step 1: Analyze the reaction shown.
The reaction shows a 1,5-hydrogen or carbon shift accompanied by formation of a new sigma bond and movement of π-electrons. Such transformations are typical of sigmatropic rearrangements.
Step 2: Why not the other options?
(A) Oxy-Cope is specific to 1,5-diene systems with –OH; not applicable here.
(C) Claisen involves allyl vinyl ethers; not relevant here.
(D) All sigmatropic rearrangements fall under pericyclic reactions, but (B) is the more specific answer.
Step 3: Conclusion.
Therefore, the given conversion represents a sigmatropic rearrangement.