which feature of a wave can be calculated using the formula below? number of wavelengths / time wavelength…

Brief Explanations:

The frequency of a wave is defined as the number of wavelengths that pass a given point per unit - time. The formula "number of wavelengths / time" represents frequency. Wavelength is the distance between two consecutive points in phase on a wave. Speed of a wave is given by the product of wavelength and frequency ($v = f\lambda$). Amplitude is the maximum displacement of a wave from its equilibrium position.

Answer:

C. frequency