Final answer:
The speed of sound is constant in a given medium, so all ultrasound frequencies will travel at the same speed in human tissue, which is approximately 1540 m/s.
Step-by-step explanation:
The speed of sound is determined by the medium through which it is traveling and not by its frequency. Therefore, when a sonographer is performing a renal ultrasound, the speed of sound in human tissue is constant, regardless of the transducer frequency being used. According to the question presented, the options for transducer frequency are 2 MHz, 4.5 MHz, and 7 MHz. However, as the speed of sound in tissue is approximately 1540 m/s, the correct answer to the question - Which transducer frequency will generate the slowest speed of sound? - is (a) All frequencies will travel at the same speed in the same tissue.