Help please :/
Our teacher wants us to solve a puzzle, but I have no idea what's going on

Which of the following could be the graph of the equation y = -2x + 5

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Answer pls man im trying to get out of summer school