Which of the following resonance structures is more stable? Explain your answer.

(A) Between the two resonance structures,structure $A$ is more stable than structure $B$.
In structure $A$,the positive charge is on the primary carbon atom,but it is an allylic carbocation,which allows for resonance stabilization.
In structure $B$,the positive charge is on the secondary carbon atom within the ring.
However,the primary reason for the stability difference is that structure $A$ has an endocyclic double bond,which is generally more stable than the exocyclic double bond present in structure $B$ due to less ring strain.