An iron rod buried inside the earth along …………… direction becomes a magnet.
(a) east-west
(b) equatorial
(c) north-south
(d) any direction

(c) north-south

Reason — The Earth itself acts as a giant magnet. When the iron rod is aligned in the same direction as the Earth’s magnetic field lines (i.e., north-south direction), it gets magnetised due to magnetic induction.