Article IV, Section 4, of the Constitution helps define the relationship between the state and federal governments by stating that:
A. all citizens are equal, no matter what their state of residence.
B. states can rely on the federal government to protect them if
needed.
C. in an area of conflict, federal law overrules state law.
D. all powers not explicitly mentioned in the Constitution belong to
the states.

The correct answer is B. states can rely on the federal government to protect them if needed.

Explanation:

This means that if a state has issues whether from across the border or domestic that the federal government will protect them. For example, if there are massive riots or forest fires or similar thing, the federal government will help pay for reconstruction of infrastructure or they will send the national guard to help with riots.