When we need to represent a coordinate on a grid we usually use the following representation: (x, y). Where x is the coordinate on the horizontal axis and y is the coordinate on the vertical axis. So we need to identify the x and y position for Mary. She is represented by the letter A on the grid, we can notice that the horizontal coordinate for that letter is 2, while the vertical one is 4. So her coordinate is (2, 4). The correct option is c.
