Read the below paragraph and answer the following questions;

Every substance has some magnetic properties associated with it. The origin of these properties lies in the electrons. Each electron in an atom behaves like a tiny magnet. The magnetic strength depends on the number of unpaired electron possessed by the element. On the basis of their magnetic properties, substances can be classified into five categories: (i) paramagnetic (ii) diamagnetic (iii) ferromagnetic (iv) antiferromagnetic and (v) ferrimagnetic.

Which among the following substance shows antiferromagnetism?

MnO 

MnO is antiferromagnetic, whereas H₂O and NaCl are diamagnetic and O2 is paramagnetic in nature.