Given the structure of 2-ethyl-2,5,5-trimethylpyrrolidin-1-ide, show its conjugate acid and choose the pK _a value from the table that could help predict the stability of the base.

• A. pK_a = 10
• B. pK_a = 38
• C. pK_a = 10
• D. pK_a = 38

Answer: (D)