For internal imaging, how does transducer frequency affect resolution and penetration, and what are typical frequencies for superficial versus deep targets?

• A. Higher frequency reduces penetration.
• B. Deep targets use 7–15 MHz.
• C. Higher frequency improves resolution but reduces penetration; superficial targets typically use 7–15 MHz, while deeper targets use 2–5 MHz.
• D. Deep targets use 20–60 MHz.

Answer: (C)