Final answer:
Option C) Lyot stop is the crucial component of a coronagraph used for reducing diffracted light, essential for the direct imaging of exoplanets.
Step-by-step explanation:
The component of a coronagraph that is essential for removing or reducing diffracted light to directly image an exoplanet is the Lyot stop. Unlike a grating prism, polarizing filter, or beam splitter, the Lyot stop is specifically designed to block out the excess light from a star that otherwise would overwhelm the faint light from an exoplanet. By strategically blocking portions of the diffracted light, the Lyot stop enhances the contrast between the star and the exoplanet, enabling astronomers to image the exoplanet directly.