Final answer:
Methanol is an example of a flammable liquid. It is used as fuel and solvent among other applications, and it must be handled with care due to its flammability.
Step-by-step explanation:
An example of a flammable liquid is methanol (D). Flammable liquids are substances that can catch fire easily at room temperature. Methanol, which is also known as wood alcohol, is a colorless liquid that burns with a flame. It is used in a variety of applications, including as fuel, solvent, antifreeze, and in the production of formaldehyde. It is important to handle methanol with care due to its flammable nature, toxicity, and potential health effects upon exposure.
Substances like potassium permanganate (A) are oxidizing agents, Drano (B) is a caustic cleaner predominantly consisting of sodium hydroxide which doesn't readily burn, and cyanuric triazide (C) is an explosive compound, not typically categorized as a flammable liquid.