15 POINTS
question 9
A student finds the slope of the line between (14, 1) and (18, 17). She writes 1 - 17 over 18 - 14. What mistake did she make?

a.
She should have added the values, not subtracted them.

b.
She did not keep the order of the points the same in the numerator and the denominator.

c.
She mixed up the x- and y-values.

d.
She used y-values where she should have used x-values.