Answer:
A-B: positive
B-C: zero
C-D: negative
Step-by-step explanation:
In a velocity-time graph, acceleration is shown by the slope or steepness of the graph. A positive acceleration means that the line of the slope is upward, while a negative acceleration means that the line of the slope is downwards.
A horizontal line shows that the acceleration is 0, which means that the object is stationary.