To determine the correct sequence, we classify each oxide based on its nature as described in the NCERT text (Class 11, Section 3.7.3 and Class 12, Section 4.4.1):

1. Neutral Oxide: NCERT explicitly lists CO, NO, and N₂O as neutral oxides. Thus, the sequence must start with NO.
2. Acidic Oxide: Oxides of non-metals are generally acidic. CO₂ is a classic acidic oxide (forms carbonic acid with water).
3. Basic Oxide: Oxides of s-block metals are basic. CaO (Calcium Oxide) is a strong basic oxide.
4. Amphoteric Oxide: Oxides that react with both acids and bases are amphoteric. ZnO (Zinc Oxide) is a well-known amphoteric oxide (along with Al₂O₃).

The required sequence is Neutral, Acidic, Basic, Amphoteric.

• Option 4: NO (Neutral), CO₂ (Acidic), CaO (Basic), ZnO (Amphoteric) fits this sequence perfectly.