Molecules/ions and their magnetic properties are given below.

Molecule/ion	Magnetic property
$(i). C_6H_6$	$(1).$ Antiferromagnetic
$(ii). CrO_2$	$(2).$ Ferrimagnetic
$(iii). MnO$	$(3).$ Ferromagnetic
$(iv). Fe_3O_4$	$(4).$ Paramagnetic
$(v). Fe^{3+}$	$(5).$ Diamagnetic

The correctly matched pairs are:

• A
  $i-5, ii-3, iii-2, iv-1, v-4$
• B
  $i-3, ii-5, iii-1, iv-4, v-2$
• C
  $i-5, ii-3, iii-1, iv-2, v-4$
• D
  $i-5, ii-3, iii-1, iv-4, v-2$