Carl and Abby are discussing what they have learned in class about electricity and magnetism. Carl tells Abby that an electric current running along a wire can be used to produce a magnetic force. Abby, on the other hand, tells Carl that moving electrons through a magnetic field can produce an electric current.  Which of the students is/are correct?   A.  Only Abby is correct.   B.  Both Carl and Abby are correct.   C.  Neither student is correct.   D.  Only Carl is correct.