Which of the given electrophilic addition reactions would you expect to be more selective toward the carbocation formation? Explain your answer.

• A. Reaction (I) is more exothermic and hence more selective for carbocation formation
• B. Reaction (II) is more exothermic and hence more selective for carbocation formation
• C. Reaction (I) is more endothermic and hence more selective for carbocation formation
• D. Reaction (II) is more endothermic and hence more selective for carbocation formation

Answer: (D)