The correct set that contains all kinds of oxides (basic, acidic, amphoteric and neutral) is:

• (1) Na₂O, N₂O, Al₂O₃ and CO
• (2) Al₂O₃, As₂O₃, CO and NO
• (3) K₂O, Cl₂O₇, As₂O₃ and NO
• (4) Na₂O, K₂O, Al₂O₃ and As₂O₃

Oxides are classified into four major categories:

• Basic Oxides: React with acids to form salt and water.
• Acidic Oxides: React with bases to form salt and water.
• Amphoteric Oxides: React with both acids and bases.
• Neutral Oxides: Neither acidic nor basic.

In Option (3):

• K₂O → Basic oxide
• Cl₂O₇ → Acidic oxide
• As₂O₃ → Amphoteric oxide
• NO → Neutral oxide

Thus, this option contains all four categories of oxides.

Final Answer

Option (3)