Answer:
A
Step-by-step explanation:
I got this answer because (by my estimation again) you are looking at 0.04 m/s which is the sound of a measure of a 2 Hz sound frequency. Therefore, for each section on the table diagrams I multiplied the period by their wavelength measurement until I got the value 0.04 m/s. In which A was the only option that gave me that value, providing me with a 2 Hz sound frequency.