The correct answer is C) You should direct the spray at the base of the fire. The reasoning for this is that with dry chemical extinguishers, you want to direct the spray at the base of the fire in order to disrupt the chemical reaction that is fueling the flames. This allows the dry chemical agent to smother and extinguish the fire effectively. Directing the spray directly into the fire (A) or at a vertical bulkhead (B) would not be as effective at disrupting the fire's fuel source. Therefore, option C is the correct approach for using dry chemical extinguishers.