Final answer:
A 2 ½-gallon fire extinguisher containing water stored under pressure would likely be effective in suppressing Class A fires.
Step-by-step explanation:
A 2 ½-gallon fire extinguisher containing water stored under pressure would likely be effective in suppressing Class A fires. Class A fires involve ordinary combustible materials, such as wood, paper, cloth, and plastics. Water is commonly used to extinguish these types of fires because it cools the fuel and removes heat.