A student tests two rods, X and Y, using the north pole of a magnet. One end of X is attracted and its other end is repelled. Both ends of Y are attracted. Which conclusion is justified?
X is unmagnetised iron; Y may be a magnet.
X is unmagnetised iron; Y must be non-magnetic.
X is a magnet; Y may be unmagnetised iron.
X is a magnet; Y must be a permanent magnet.