What is the difference between a snaffle bit and a curb bit in terms of action?

What is the difference between a snaffle bit and a curb bit in terms of action?

• A. A snaffle uses leverage via the curb strap.
• B. A snaffle acts directly on the mouth with leverage.
• C. A curb bit has no leverage.
• D. A snaffle acts directly on the mouth with no leverage; a curb bit applies leverage via the curb strap/chain and often requires lighter rein aids.

Answer: (D)