Explain ring-down artifact and how damping and pulse duration influence it.

• A. Ring-down is residual oscillation after the transmit pulse; shorter pulse duration has no effect.
• B. Ring-down is a synchronization artifact in Doppler.
• C. Ring-down is residual oscillation after the transmit pulse; increased damping and shorter pulse duration reduce ring-down.
• D. Ring-down only occurs in non-ultrasound imaging.

Answer: (C)