The correct answer is C. Motion of charged particle in electromagnetic fields.
An electron microscope is a type of microscope that uses electrons to create an image of a sample. The electrons are accelerated to a high energy and then focused onto the sample using electromagnetic fields. The electrons interact with the atoms in the sample, and the resulting image is magnified and displayed on a screen.
Option A is incorrect because optical interference is a phenomenon that occurs when light waves interact with each other. Electron microscopes do not use light waves, so optical interference is not involved in their operation.
Option B is incorrect because the wave nature of electrons is not the only principle that governs the operation of an electron microscope. The motion of charged particles in electromagnetic fields is also important.
Option D is incorrect because Faraday’s law of electromagnetic induction is a law that describes how a changing magnetic field induces an electric current. This law is not relevant to the operation of an electron microscope.