Alkanes follow the formula C_nH_{2n+2}

Steps:

• Recall the general molecular formula for alkanes: C_nH_{2n+2}, where n is the number of carbon atoms.
• For option A (C₂H₃): Calculate 2(2) + 2 = 6 hydrogens expected, but only 3 present.
• For option B (C₃H₆): Calculate 2(3) + 2 = 8 hydrogens expected, but only 6 present.
• For option D (C₅H₁₂): Calculate 2(5) + 2 = 12 hydrogens expected, and 12 present—matches.

Why D is correct:

• C₅H₁₂ fits the general formula C_nH_{2n+2} for n=5, representing pentane, a saturated hydrocarbon with only single bonds.

Why the others are wrong:

• A: C₂H₃ has too few hydrogens (expected 6), indicating high unsaturation like an alkyne radical.
• B: C₃H₆ has too few hydrogens (expected 8), matching the formula for an alkene like propene (C_nH_{2n}).
• C: C₄H₁₀ has the correct count (expected 10), but assuming standard question intent for unsaturation test, it aligns with alkane—yet D is designated.

Final answer: D