In the Scooby Doo analogy, what role does the inhibitor play?

The inhibitor is like a character that prevents Scooby from solving the mystery, regardless of his actions.

The inhibitor is like a character that helps Scooby solve the mystery faster.

The inhibitor is like a character that competes with Scooby for clues.

The inhibitor is like a character that ignores Scooby's actions entirely.