easy but confused still?

its D 

 

just flip the line around

When you reflecting a point in the x - axis, you multiply -1 to the y - coordinates to get the coordinates of the new point. same as a line.

 

Coordinates of D = (4 , -3)

Therefore Coordinates of D' = (4 , -3*-1) = (4 , 3)

Coordinates of F = (-2 , 4)

Therefore coordinates of F' = (-2 , -1 * 4) = (-2 , -4)