Answer :
Final answer:
Class B fire extinguisher should be used to safely extinguish a flammable liquid.
Explanation:
The class of fire extinguisher that should be used to safely extinguish a flammable liquid is Class B. Class B fire extinguishers are designed to extinguish fires involving flammable liquids such as gasoline, oil, and grease. They use a dry chemical or foam-based agent to smother the fire and prevent re-ignition.