Answer:
A, the needs of the nation have changed.
Step-by-step explanation:
By the way, the answers to the whole Unit Test Review are here:
1: A.
2: D.
3: B.
4: A.
5: A.
6: B.
7: C.
8: B.
9: A.
10: A.
11: C.
12: A.
13: D.
14: B.
15: C.
You're Welcome :)