Answer:
(B) Time zones sometimes follow the borders of countries
Step-by-step explanation:
Let's prove why each other statement is false.
A: Time zones are based on hours and they are determined through lines of latitude (15 degrees longitude each). So this is false.
C: Time zones boundaries are not perfectly vertical, as all boundaries in the US alone are not vertical, they follow a jagged line. This is also false.
D: Time zones are based on lines of latitude, meaning they run North-South, so they cant run East-West. This is false.
This leaves B.
Hope this helped!