GKFix MCQ Question

What is the ionization constant of the conjugate acid of aniline? (Kb=4.3×10⁻¹⁰)

• A. 2.33 × 10⁻⁵
• B. 4.3 × 10⁻¹⁰
• C. 1.0 × 10⁻¹⁴
• D. 5.0 × 10⁻⁴