The coordinates of a quadrilateral are (5, 8), (7, 10), (9, 12), and (11, 14). after a transformation, the sign of the x-coordinate for each ordered pair has changed. which type of transformation occurred?
a) (x, y)→(x + 2, y + 2)
b) dilation; (x + 2), (y + 2)
c) reflection across the y-axis
d) reflection across the x-axis

Given:
1st point (5,8)
2nd point (7,10)
3rd point (9,12)
4th point (11,14)

After transformation, the sing of the x-coordinate for each ordered pair has changed. From positive, it becomes negative. However, the sign of the y-coordinate is assumed to retains its original sign. 

From positive x and positive y to negative x and positive y, this is C. REFLECTION ACROSS THE Y-AXIS.