Final answer:
On a speed-time graph, a graph of constant speed would show as a horizontal line, indicating that the object is moving at a steady, unchanging pace with zero acceleration.
Step-by-step explanation:
On a speed-time graph, a graph of constant speed would show as B. a horizontal line. This type of graph indicates that the object is moving at a steady pace without speeding up or slowing down. The speed does not change over time, which means there's zero acceleration - the object's velocity remains constant. A horizontal line on a speed-time graph denotes that the object's speed is not changing with time. Angles down or up would suggest deceleration or acceleration, respectively, and a staggered line would indicate variable speed.