The correct answer is: C. Lenient.
Rigid means inflexible, strict, or unyielding. It is the opposite of lenient, which means forgiving, tolerant, or understanding.
Merciful means showing mercy or compassion. It is the opposite of cruel or harsh.
Generous means giving or sharing freely. It is the opposite of selfish or stingy.
Tolerant means able or willing to accept views, beliefs, or behavior that is different from one’s own. It is the opposite of intolerant or bigoted.
In the context of the question, the correct answer is C. Lenient. This is because a lenient person is more likely to forgive or overlook mistakes, while a rigid person is more likely to be strict and unforgiving.