made the system look ridiculous is correct because make a mockery of means to make something seem foolish, false, unfair, or not worthy of respect.

This idiom or phrase is useful because it helps students understand the intended meaning beyond the individual words.

Examples: The unfair decision made a mockery of the rules. Ignoring the evidence made a mockery of the trial.

The idiom means the system was treated as ridiculous or unfair, not merely that people laughed at it.