Which statement best describes the trade-off between catheter diameter and acoustic frequency in IVUS transducers with respect to resolution and penetration in vessel walls?

• A. Smaller catheter diameters limit array size but are necessary for vascular navigation; higher frequency improves resolution but reduces penetration depth.
• B. Larger catheter diameters always improve resolution.
• C. Higher frequency increases penetration depth but reduces resolution.
• D. Smaller diameters improve penetration but reduce navigation.

Answer: (A)