Final answer:
Increasing the transducer frequency improves axial resolution by using a smaller wavelength but can decrease lateral resolution due to increased absorption of the sound wave in the medium(option c).
Step-by-step explanation:
The question relates to the effects of changing the frequency of a transducer in the context of ultrasound physics. When the frequency of a transducer is increased, option C) "Increase axial resolution but decrease lateral resolution" is correct.
A higher frequency transducer produces a sound wave with a smaller wavelength, which in turn improves axial resolution. Axial resolution refers to the ability to distinguish between two structures that are close to each other along the path of the sound wave. However, a higher-frequency sound wave is more readily absorbed by the medium it travels through, which can reduce the lateral resolution — the ability to differentiate two structures that are side by side.