Step-by-step explanation:
A positive : from left to right it goes up.
B negative : from left to right it goes down.
C negative : from left to right or goes down.
D positive : from left to right it goes up.
a zero slope would be a horizontal line (not going up, not going down, just a flat line).
an undefined slope would be a vertical line. x cannot change at all, but y takes every value from -infinity to +infinity at the same time.
