Correct option is C
• Mg (Magnesium) has 12 electrons → configuration: 2,8,2 → (IV)
• Na (Sodium) has 11 electrons → configuration: 2,8,1 → (III)
• Li (Lithium) has 3 electrons → configuration: 2,1 → (I)
• Cl (Chlorine) has 17 electrons → configuration: 2,8,7 → (II)
Thus, the correct matching is: A–IV, B–III, C–I, D–II