Final answer:
The correct answer to the student's question is that when hydrocarbons are burned in a limited amount of air, carbon monoxide is produced rather than complete combustion which yields only carbon dioxide and water.
Step-by-step explanation:
When hydrocarbons are burned in a limited amount of air, carbon monoxide is produced. Complete combustion, which yields carbon dioxide and water, requires sufficient oxygen. In instances where oxygen is scarce, the product is typically carbon monoxide, a lethal gas that can cause fatalities if emitted in poorly ventilated spaces from gas or kerosene heaters. The correct answer to the question is option a) carbon monoxide is produced.