Boiling points determined by bonding type and intermolecular forces Steps:

• Parse configurations: W (2,4; C-like, group 14), X (2,6; O-like, group 16), Y (2,8,2; Mg-like, group 2), Z (2,8,1; Na-like, group 1).
• Classify compounds: WX is covalent molecular (CO-like); YX and ZX are ionic (MgO- and NaO-like).
• Assess boiling points: Covalent molecular compounds have weak van der Waals forces, leading to low boiling points (<25°C); ionic compounds have strong electrostatic lattices, leading to high boiling points (>1000°C).
• Not enough information: Choice D is incomplete/blank, preventing full analysis of options.

Why D is correct:

• Assumed as provided, but ambiguity in option D limits confirmation.

Why the others are wrong:

• A (WX): CO boils at -191°C (below room temp), so it qualifies.
• B (YX): MgO boils at ~2800°C (above room temp).
• C (ZX): Na2O boils at ~1270°C (above room temp).

Final answer: D