Question

To measure one wavelength, you would measure the distance between?

Answer 1

A and B, one wavelength is crest too crest

Answer 2

Answer: A and B

Explanation: The wavelength is defined as the distance between two consecutive equivalent points in the wave. (two consecutive crests, two consecutive valleys, etc)

This would be in the graph the distance between the points A and B, or between E and F.

Then the right answer between the given ones is the fourth: A and B.