The change in flux linkages can be caused in which of the following ways ?

The change in flux linkages can be caused in which of the following ways ?

A. The flux is constant with respect to time and is stationary and the coil moves through it
B. The coil is stationary with respect to flux and the flux varies in magnitude with respect to time
C. Both the changes mentioned above occur together, i.e., the coil moves through a time varying field
D. All of the above