Question

Line CD contains points A (4, 6) and B (−2, 6). What is the slope of the line CD?

Answer 1

The slope of the line given the points is calculated through the equation,
                                 m = (y2 - y1) / (x2 - x1)
Substituting the known values,
                                 m = (6 - 6) / (-2 - 4)   = 0
The slope of the given line is equal to 0 which means that it is a horizontal line. 

Answer 2

so is it a b c or d?

zero

undefined

positive

negative