Answer:
They waited before crossing a busy street
Explanation:
Assume the graph looks like the one below.
It shows that, from Point B to C, the distance they were from home did not change. They had stopped.
A possible interpretation is that they waited before crossing a busy street.
If they had begun accelerating, BC would have been steeper than AB.
If they had slowed their walk, BC would still point up. However, its slope would be less than that of AB.
If they had returned home, BC would point down and to the right.
