Correct Answer: Cruel and unfair

Solution : The right choice is the third option .

Below the belt is used metaphorically to describe actions or comments that are unfairly hurtful or inappropriate, much like in boxing, where a hit below the belt is illegal and not sportsmanlike. The idiom implies crossing the boundaries of fair play or decency in any context, not just in sports.

Therefore, the most appropriate meaning of the given idiomatic expression is, cruel and unfair.