The correct answer should be A. Proverb.

- Proverb: This statement is a piece of wisdom or advice, commonly known and used, which is characteristic of proverbs.

- Metaphor: While the phrase uses a metaphorical concept (chasing rabbits as a metaphor for attempting to do too many things at once), it is primarily recognized as a proverb.

- Figure of Speech: This is a broader category that includes metaphors and proverbs, but "proverb" is the most accurate specific term here.

So, the best answer is A. Proverb.