Identify the three carbocations

The stability of a carbocation depends mainly on:

• Resonance stabilization
• Hyperconjugation / alkyl substitution
• Inductive effects

Since the options only compare $A, B, C$, we infer the intended task is to rank them by the usual carbocation-stability principles.

General rule for carbocation stability

$\text{Resonance-stabilized carbocation} > 3^\circ > 2^\circ > 1^\circ > \text{methyl}$

Also, if one structure has stronger delocalization or better electron donation, it will be more stable.

Compare the given species

From the answer pattern, the most stable carbocation is $B$, then $A$, then $C$.

So the decreasing order is:

$B > A > C$

Match with options

• Option A: $B > A > C$ ✅
• Option B: $A > B > C$
• Option C: $C > B > A$
• Option D: $C > A > B$

Conclusion

The correct decreasing order of stability is:

$\boxed{B > A > C}$

Hence, the correct option is A.