al phy inductance mc

With a soft iron core inserted, the inductance of the coil increases, also with the coil having no resistive component, the resistance of the whole circuit is still the same, implying that the final current value will still be the same. Thus by the formula:

L dI/dt = E at initial state, where E is the emf of the cell

the initial rate of increase of current becomes slower than before inserting the iron core.

Hence ans = D