Answer:
The answer is that a(t) is decreasing from 5 to 6 minutes.
Explanation:
The other answers do not make sense, except for one which may be confusing. That answer is that a(t) is negative from 5 to 6 minutes.
The graph, however, while decreasing, is never negative, as the distance can never be a negative measurement. Nor is the graph slanted up and to the left.