Final answer:
Free-base cocaine carries an increased risk of flammability due to its volatile nature, vaporizing at low temperatures such as that of a burning cigarette.
Step-by-step explanation:
The type of cocaine that carries the increased risk of flammability is B. free-base cocaine. Free-base cocaine is more volatile than other forms of the substance like cocaine hydrochloride or coca-leaf powder.
This is because free-base cocaine vaporizes at the temperature of a burning cigarette, making it particularly dangerous when it comes to the risk of fire. In contrast, cocaine hydrochloride is water-soluble and commonly snorted, and therefore does not carry the same flammability risk when used in this way.