The correct answer is (B) unfitness; the state or quality of being inept; inept remark, act, or other thing. Also, foolishness, silliness, or lack of good judgement.

Ineptitude comes from Latin ineptitudo

Examples of use:

• He displayed an extraordinary ineptitude in his handling of foreign affairs.
• The team's losing record last year was the result of laziness and ineptitude.