Question

which piece of equipment will help a firefighter increase or decrease the pressure of fluid to fight a fire?
hose
hydrant
wrench
valve

Explanation:

A valve can control the flow rate of fluid, which in turn can increase or decrease the pressure. A hose is just for transporting fluid, a hydrant is a water - source connection point, and a wrench is a tool for tightening or loosening, not for controlling fluid pressure.

Answer:

D. valve