The two basic types of compressors used in gas turbine engines are which of the following?

Correct Answer: Option D — Centrifugal and axial.

Gas turbine engines primarily utilize centrifugal and axial flow compressors to increase air pressure before combustion. Axial compressors use rows of rotating blades and stationary vanes to move air parallel to the shaft, while centrifugal compressors accelerate air radially, both serving to compress the working fluid for the Brayton cycle.