He took exactly four years
D is the correct answer.
In the badly drawn diagram attached, you will find the <em>yellow</em> represents wavelength, which is the distance between identical points on consecutive waves.
The <em>green</em> represents the amplitude, which is the distance between the origin (middle) and crest/trough (top/bottom)
It 4 square mark me brainliest
Write a thesis statement<span> identifying the issue and your position. Construct an outline which has the primary main ideas supporting your position and one or two opposing arguments for refutation. Choose a pattern of organization which is logical and convincing.</span>