ANS=A , in this reaction to get ans A we need to break epoxide ring in a way such that carboncation is form at alpha carbon to carbonyl group which is highly unstable.
The carbocation formed will be in resonance but still the resonating structure will have O+ which is very stable in this case .
I think option B should have been the correct answer !
Breaking epoxide such that it forms C+ near carbonyl doesn’t seem correct to me
Answer should be D if we rotate the compound .
Option A is correct ! It’s like like a special case , this question came once in olympiad .
It is forming carbocation at right ring not because of stability of C+ factor rather the C=O bond then forms H bonding with the OH formed after epoxide is cleavaged
It is similar to pinacol pinacolone mechanisism .
Though carbocation formed is unstable it is formed such that ring expands to form carbonyl compound(which is highly stable).