give a false alarm is correct because cry wolf means to give a false alarm or warn people about danger when there is no real danger.

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

Examples: If you cry wolf too often, people may not believe you when real danger comes. The boy cried wolf as a joke, but the villagers stopped trusting him.

The idiom is about false warnings, not anger, roads, or showing teeth.