Explanation: The basic unit of electrical power is the **Watt**. Electrical power measures the rate at which electrical energy is consumed or produced. In the context of radio theory, power is a crucial concept, as it determines the strength of a transmitted signal or the energy dissipated by components. The other options are incorrect: * **Ohm** is the unit of electrical resistance, measuring opposition to current flow. * **Volt** is the unit of electromotive force (EMF) or potential difference, representing the electrical "pressure" that drives current. * **Ampere** is the unit of electrical current, measuring the rate of flow of electric charge. These units are all related by Ohm's Law and the power formula (P = V × I), but only the Watt specifically quantifies power.