Acidic oxides \(\rightarrow \mathrm{Mn}_2 \mathrm{O}_7, \mathrm{CrO}_3, \mathrm{~V}_2 \mathrm{O}_5\)
(due to higher oxidation state of central metal)
Basic oxide \(\rightarrow \mathrm{Na}_2 \mathrm{O}, \mathrm{CaO}, \mathrm{BaO}\)
(due to lower oxidation state of central metal)
Alkaline and alkali metal oxide are always basic.
Neutral oxides \(\rightarrow \mathrm{CO}, \mathrm{NO}, \mathrm{N}_2 \mathrm{O}\)
Amphoteric oxides \(\rightarrow \mathrm{ZnO}, \mathrm{PbO}, \mathrm{BeO}\)
(acidic as well as basic)
Hence, option (4) is correct.