Correct Answer: Meaningful

Solution : The correct choice will be the second option.

Irrelevant: It means not connected or applicable to the matter; not important or pertinent.

Meaningful: It denotes having significance or purpose, conveying a clear message or importance.

In the context of the sentence, if the rules are perceived as "irrelevant" then the opposite, or antonym, would be "meaningful"—rules that have significance or relevance to the situation.

The meanings of the other words are:

Reluctant: This term refers to a feeling of unwillingness or hesitation.

Meagre: This word describes something insufficient or lacking, often in quantity or quality.

Incidental: It denotes something that is not of primary importance but rather happens by chance or as a secondary consequence.

Therefore, the correct answer will be meaningful.