Final answer:
Option (D), The projector lens is unique to electron microscopes and is not found on light microscopes. It projects the electron image onto a viewing device.
Step-by-step explanation:
The lens found on electron microscopes but not on light microscopes is the projector lens. While both electron and light microscopes have components such as the condenser lens, eyepiece lens, and objective lens, the projector lens is unique to electron microscopes.
It is used to project the image created by the electromagnetic lenses onto a photographic plate, screen, or sensor for viewing and capturing. Electron microscopes, like the transmission electron microscope, require these specialized lenses due to the nature of electron imagery, which differs from the light microscopy used in brightfield or darkfield microscopes.