Primary origin of magnetism lies in

Primary origin of magnetism lies in :

a) Atomic currents
b) Pauli exclusion principle
c) Polar nature of molecules
d) Intrinsic spin of electron

(1) Only d
(2) b, d
(3) a, d
(4) c, d

The correct answer is (3) a, d.
Primary origin of magnetism lies in atomic currents and intrinsic spin of electron.