Question

what has been one factor in the growing role of the federal courts over time?
judges have been willing to hear more cases.
the fact that there are more federal laws that need to be interpreted.
decisions by congress and the president to limit the types of cases the courts could hear.
fewer state courts means there is a need for more federal courts.
rewatch submit

Explanation:

The federal courts' role grows as more federal laws need interpretation. Federal courts interpret federal laws. More laws mean more cases for interpretation, expanding their role. Judges' willingness (first option) is not a systemic factor. Limiting cases (third option) would reduce, not grow, their role. State courts' number (fourth option) is not the main factor as federal courts handle federal - law - related cases.

Answer:

The fact that there are more federal laws that need to be interpreted.