Explanation:

- "The bee’s knees" is an idiom that means something or someone is of excellent quality or extraordinary.

- Extraordinary: This is the correct meaning. The phrase is often used to describe something outstanding or excellent.

- Observant: This means being watchful or noticing things. It doesn't relate to the idiom.

- Problematic: This means causing problems or difficulties. It's not relevant to the positive connotation of the idiom.

- Foolish: Describes lack of good sense or judgment, which isn't connected to the idiom.

- Correct Answer: Extraordinary