GKFix MCQ Question

Why is the ionisation enthalpy of Mn+ lower than that of Cr+ according to the text?

• A. Mn+ has a 3d54s1 configuration while Cr+ has a d5 configuration, making Mn+ easier to ionise
• B. Cr+ has a more stable configuration than Mn+
• C. Mn+ has a higher nuclear charge
• D. Cr+ has a lower effective nuclear charge