The answer would be the first choice. When you reflect a shape across the x-axis, the y coordinates of every points/vertices become of the opposite of what they usually were.
For example, the y coordinate in (1, -5) {{-5 being the y coordinate) once reflected upon the x axis would be (1, 5).
On the other hand, if the y coordinate were positive it would become negative.
8 x 45 = 8(40 + 5) = 320 + 40 = 360
