Explanation: Power (P) is the rate at which energy is consumed, transferred, or radiated. The fundamental formula relating power to current (I) and resistance (R) is derived from Ohm's Law (E = I * R, where E is voltage) and the basic power formula (P = E * I). By substituting E in the power formula with I * R, we get P = (I * R) * I, which simplifies to **P = I²R**. This formula directly calculates power given the current flowing through a resistance, making it ideal for determining power at the base of an antenna where current and feedpoint resistance are known. Option A, P = watts x amps, is dimensionally incorrect; power is measured in watts, and multiplying watts by amps does not yield power. Option C, P = current x resistance (P = I * R), is actually the formula for voltage (E = I * R) according to Ohm's Law, not power. Therefore, B is the only correct power formula in this context.