What is the difference between policing and shaping?

What is the difference between policing and shaping?

A.
Policing: Transmit and mark, then transmit the packets. Shaping: Buffer the exceeding packets.

B.
Policing: Transmit the packets. Shaping: Buffer the exceeding packets.

C.
Policing: Transmit, drop or mark, then transmit the packets. Shaping: Buffer the exceeding packets.

D.
Policing: Buffer the exceeding packets. Shaping: Transmit and mark, then transmit the packets.