What is density altitude, and why does it matter for takeoff performance?

What is density altitude, and why does it matter for takeoff performance?

• A. Density altitude is identical to field elevation.
• B. Density altitude only affects landing.
• C. Density altitude is a measure of air density adjusted for pressure; higher density altitude reduces air density, lowering thrust and lift and increasing takeoff distance.
• D. Density altitude is the altitude of the aircraft's cockpit height.

Answer: (C)