Please explain
1. The correct option is (4).
2. This is because, among all the secondary carbocations, this carbocation has larger alkyl groups attached at both sides.
3. Larger alkyl groups have more +R effect, which enhances to stability of electron deficient carbocation.
2. This is because, among all the secondary carbocations, this carbocation has larger alkyl groups attached at both sides.
3. Larger alkyl groups have more +R effect, which enhances to stability of electron deficient carbocation.