Question

the practice of selective incorporation means that the bill of rights will
always be applied to the states by the court.
never be applied to the states by the court.
sometimes be applied to the court by the states.
sometimes be applied to the states by the court.

Explanation:

Selective incorporation is the process by which the Supreme Court applies parts of the Bill of Rights to the states on a case - by - case (or "selective") basis. This means that the Bill of Rights is not always applied to the states (so the first option is wrong), nor is it never applied (so the second option is wrong). Also, the application is from the Court to the states, not the other way around (so the third option is wrong). So the correct understanding is that the Bill of Rights is sometimes applied to the states by the Court.

Answer:

D. sometimes be applied to the states by the Court.