Answer:
A and E.
Step-by-step explanation:
A slope is part of the definition of a lineal function, with it we can know the behaviour of the function graph. This is crucial to lineal models applied to real problems.
So, when a line moves up from left to right, we say that has a positive slope.
On the other hand, when it moves down from left to right, we say is negative.
But, there are cases when lines don't have a specific slope, for example, vertical lines have undefined slope, because their inclination tend to infinite.