[单选题]
An electric generator tro c4ev,nx-7 ynf/pf .cjmlb2duq0 6 f:aezqnl-gsh1muk *x7:2f 5i ee(nsforms
A. electrical energy into mechanical energy.
B. mechanical energy into electrical energy.
C. direct current into alternating current.
D. alternating current into direct current.
