Three factors that are required to be present for electro-magnetic induction to occur are an electrical conductor, magnetic lines of flux and ____.

A) relative motion between the two
B) turns of wire
C) current flow
D) magnetic field

In order for electromagnetic induction to occur, there must be relative motion between the electrical conductor and the magnetic lines of flux. This relative motion creates a change in the magnetic field, which in turn induces an electrical current in the conductor. The presence of turns of wire or current flow may be helpful in creating or detecting the induced current, but they are not necessary for electromagnetic induction to occur.