Answer:
A: rising (angle, up)
B: steady at high (horizontal)
C: falling (angle, down)
D: steady at bottom (horizontal)
Explanation:
as the bus starts moving and increases speed over time, the line rises, showing how the bus is gaining speed over the course of 1 min
then the stayed at the higher speed wile it traveled for x amount of time to get to the destination, so the line stayed steady as well
as it started to slow down, the speed decreased, and so does the line on the graph, this goes on for one more minute
then the bus stops to let off the passengers, it stays at 0mph for 2 mins, so the line rests at 0 for two mins on the line
note: at NO POINT should the line be vertical, else it would NOT be a function, the bus takes time to accelerate and decelerate, if the line between transitions were vertical the bus would go from 30 mph to 0 in no time, no literally, at that point you would have multiple x values for 1 y value, both the top of the line at 30mph, the bottom of the line at 0 and ALL the speeds in between, so VERTICAL LINES SHOULD NOT BE USED
hope this helps