Answer: C; interact with charged particles.
Explanation: The elctromagnetic force is defined as:
F = q*E
Where q is the charge of a particle or charged object, and E is the electrical field, where the direction of the electric field defines the direction of the force.
Then, we need to have a charged particle in a outer eletrical field to have a electromagnetic force, which means that the correct answer is the option C; interact with charged particles.