SN1 Mechanism Energy Profile Steps:

• Recognize the mechanism as SN1: slow unimolecular dissociation to carbocation intermediate, followed by fast nucleophilic attack.
• Sketch energy diagram: reactants high, large Ea for slow step to high-energy carbocation intermediate, small Ea for fast step to lower-energy products (exothermic overall).
• Look for diagram showing single deep intermediate valley after first high barrier, then shallow drop to products below reactants.
• Match to options: select diagram with these features.

Why B is correct:

• B depicts a high-energy intermediate after a tall first barrier and a short second barrier leading to exothermic products, matching the slow-fast SN1 steps per transition state theory.

Why the others are wrong:

• A: Shows concerted single step with no intermediate, unlike two-step mechanism.
• C: Symmetric barriers indicate equal rates, not slow first step.
• D: Endothermic profile with products above reactants, contradicting exothermic hydrolysis.

Final answer: B