Effectiveness depends on CO₂ yield per unit mass Steps:

• Calculate molar mass and CO₂ mass for each mineral's decomposition.
• Baryte (BaCO₃): 197 g/mol, yields 44 g CO₂ (fraction 0.223).
• Dolomite (CaMg(CO₃)₂): 184 g/mol, yields 88 g CO₂ (fraction 0.478).
• Huntite (CaMg₃(CO₃)₄): 352 g/mol, yields 176 g CO₂ (fraction 0.5).
• Order by descending CO₂ fraction: huntite > dolomite > baryte.

Why D is correct:

• Huntite releases the most CO₂ per gram (50%), followed by dolomite (47.8%) and baryte (22.3%), maximizing fire-smothering per mass.

Why the others are wrong:

• A: Repeats huntite incorrectly and omits baryte.
• B: Repeats huntite and ignores baryte.
• C: Repeats dolomite and excludes baryte.

Final answer: D