Answer :
The correct answer for this question is this one:
"Your friend says that the graph is not continuous because it stops at d = 5, so the graph is discrete." Your friend is wrong. The graph is still continuous because the graph shows continuity. The problem only shows the graph at certain t time. This means that the graph can be extended at any t time.
"Your friend says that the graph is not continuous because it stops at d = 5, so the graph is discrete." Your friend is wrong. The graph is still continuous because the graph shows continuity. The problem only shows the graph at certain t time. This means that the graph can be extended at any t time.