Which one of the following comparators is based on the principles of optics, using illumination, lenses, and mirrors to project a magnified silhouette of the part onto a viewing screen?

Correct option is C

Given question: Which comparator uses optics, illumination, lenses, and mirrors to project a magnified silhouette?
Step 1: Understand the types of comparators
Mechanical Comparator: Uses levers and gears to amplify small displacements.
Electro-Mechanical Comparator: Combines mechanical amplification with electrical measurement.
Optical Comparator: Uses light, lenses, mirrors to project a magnified image of the part on a screen for measurement.
Pneumatic Comparator: Uses air pressure to detect small differences in dimensions.