the distance shown in the diagram is known as the\na amplitude.\nb crest.\nc trough.\nd wavelength.

Brief Explanations:

The distance between two consecutive points in phase (e.g., two crests or two troughs) on a wave is the wavelength. Amplitude is the maximum displacement from the equilibrium position. A crest is the highest - point on a wave and a trough is the lowest - point. The distance shown is between two like - points on the wave, which is the wavelength.

Answer:

D. wavelength