Question

which of the following best describes how the constitutions authority extended to individual states?
only northern states had to obey it.
only southern states had to obey it.
only states that ratified it had to obey it.
only states that rejected it had to obey it.

Explanation:

The US Constitution's authority over states was based on ratification. States that ratified the Constitution agreed to be bound by it; the division between Northern and Southern states (as in A and B) is incorrect, and states that rejected it (D) wouldn't be bound. So the correct reasoning is about ratification leading to obedience.

Answer:

C. Only states that ratified it had to obey it.