The u. s. constitution gives congress the power to
conduct trials in the u. s. supreme court
combine state and federal trial courts
create inferior courts as necessary
close the state courts during a u. s. trial

The U.S constitution gives congress the power to: Create inferior courts as necessary

The only court that directly created by the Constitution is the Supreme court. But it mentioned that the congress can create lower federal court 'from time to time'. This mean that creating a lower court is allowed if necessary, especially for handling smaller cases that can take away the time/attention of the supreme court justices.

i think the answer is b.