Answer: D
Explanation: When you need to look for a wave with the most energy, you need to look at you answers and analyze them. Number A will have the least amount of energy because it uses the least amount of the line. D is the correct answer because the top and bottom of the red line are both equal making a balanced energy source and it uses the most of the black line as possible. This makes sure that the energy goes faster and more effectively. The closer the lines, the more energy it carries. Hope this helped :)