Answer:
d. At the base of the fire
Explanation:
Most fire extinguisher utilize the non-combustible nature of carbon-dioxide . carbon-dioxide is what is used in fire extinguishers, because it does not support burning. Also, carbon-dioxide is denser than air, allowing it to sink down. Aiming at the bottom of the flame allows the carbon-dioxide to sink down on the base of the flame, covering the base of the fire, and cutting off its supply of oxygen which is vital for combustion.
