Line M passes through the points (–5, 9) and (–1, 9).

Which is true of line M?

A) Line M is a vertical line with an undefined slope.
B) Line M is a vertical line with a slope of zero.
C) Line M is a horizontal line with an undefined slope.
D) Line M is a horizontal line with a slope of zero

Line M passes through the points 5 9 and 1 9 Which is true of line M A Line M is a vertical line with an undefined slope B Line M is a vertical line with a slop class=