Sulfur as a fossil fuel contaminant Steps:

• Identify X as sulfur: solid at room temperature, common contaminant in fossil fuels, forms SO₂ (Y) upon combustion, which oxidizes to SO₃ (Z) in air.
• Evaluate statement 1: Sulfur's configuration is [Ne] 3s² 3p⁴, so it has p electrons.
• Evaluate statement 2: The problem states Y (SO₂) oxidizes to Z (SO₃) in the atmosphere, confirming this.
• Evaluate statement 3: Y (SO₂) + H₂O → H₂SO₃ (sulfurous acid), a weak acid (pKₐ ≈ 1.9), not strong.

Why B is correct:

• B selects statements 1 and 2, matching sulfur's properties and the described chemistry.

Why the others are wrong:

• A omits correct statement 2.
• C includes false statement 3 and omits correct statement 1.
• D includes false statement 3.

Final answer: B