Which statement best differentiates hydraulic and pneumatic systems?

Which statement best differentiates hydraulic and pneumatic systems?

• A. Hydraulics use incompressible liquids with high energy density and high forces; typical pressures tens to hundreds of bar; slower to moderate response.
• B. Hydraulics use compressible gas with low energy density.
• C. Pneumatics use incompressible liquids.
• D. Both rely on incompressible liquids.

Answer: (A)