Answer: B. Liquids are incompressible.
Liquids are well suited for hydraulics due to their incompressibility and stiffness. With this, they are able to provide powerful and durable energy transmission in a hydraulic system leading to actuators having a satisfying completion of work in both rotary and linear motions. Hydraulic fluids can also be used in cooling a system. Hydraulic fluid is capable of dispersing heat in a hydraulic system by taking the heat away from the devices. Hydraulic fluids can also serve as lubricants. The primary reason however why liquids are used in hydraulics is basically due to their incompressibility.