What does the elastic clause do?
It tells states to cooperate with each other.
It explains what duties state government has.
It allows the federal government to expand its powers.
It shifts power from the federal government to the states.

The elastic clause is the explanation in the constitution that clearly states that congress may use their powers to fulfill their duties. The closest answer I see to this in the given options appears to be “It allows the federal government to expand its powers.” Hope that helps!