Question

which statement is correct?
a horizontal line has no slope.
a vertical line has a slope of zero.
a line that rises from left to right has a positive slope.
a line that falls from right to left has a negative slope.

Explanation:

The slope of a horizontal line is 0 (can be considered as having 'no non - zero slope'). A vertical line has an undefined slope. A line rising from left to right has a positive slope and a line falling from left to right has a negative slope. So the statement about the horizontal line is correct.

Answer:

A. A horizontal line has no slope.