The student’s teacher tells him to revise his plan because no valid conclusions can be drawn. How should he fix his plan so conclusions can be drawn? The student’s teacher tells him to revise his plan because no valid conclusions can be drawn. How should he fix his plan so conclusions can be drawn?

A. The student could add a trial using 500 turns of the wire.

B. The student could add a trial with a medium strength magnet.

C. The student could do several trials with the same number of turns of the wire and the same strength of magnet and change the rotations per minute of the magnet.

D. The student could do several trials with the different numbers of turns of the wire and different strength magnets but keep the rotations per minute of the magnet the same.