Which statement does not describe a linear relationship?

A All linear equations are straight lines.
B All linear equations must cross the x-axis.
C If the slopes of two lines are the same, the lines go in the same direction.
D If the y-intercepts of two lines are the same, the lines cross the y-axis at the same point.



-note that when it is linear the graph is a line. 
that makes choice A true 
-two lines with the same slope are called parallel lines. they won't meet at any point (theoretically) and does have the same direction. that makes choice C true 
-if two lines are having the same y-intercept, they would intersect at that same point in the y-axis. this makes choice D true
-note that a line could have an equation say y=3 which makes the value of y always equal to 3 and the value of x in infinity and doesn't intersect the x-axis. this line is parallel with the x-axis and won't have an x-intercept (theoretically) 
therefore the answer is B