Which of the following is a component that stores electric charge?

A capacitor is a component that stores electric charge. It consists of two conductive plates separated by an insulating material, known as a dielectric. When a voltage is applied across the plates, positive and negative charges accumulate on the plates, creating an electric field between them. The amount of charge a capacitor can store is directly proportional to the voltage across it and its capacitance (measured in farads).

This ability to store charge makes capacitors crucial in various electrical applications, such as filtering signals, smoothing out voltage fluctuations, and timing circuits. Unlike other components listed, such as inductors, transistors, and diodes, which have distinct functions like storing energy in a magnetic field, amplifying signals, and allowing current to flow in one direction, respectively, the primary role of a capacitor is specifically centered around its capability to hold and release electric charge.