What is the general assumption regarding antennas?

Antennas are generally considered active components in the context of telecommunications because they are essential in the transmission and reception of radio frequency signals. When in operation, antennas convert electrical energy into electromagnetic energy for transmission, as well as convert received electromagnetic energy back into electrical energy for processing. This active role is crucial in enabling communication systems to function effectively, making the assumption that antennas are active appropriate in understanding their role and functionality within the telecommunications infrastructure.

Given this context, the other options do not align with the primary characteristics of antennas. For instance, stating that antennas are inactive or should be turned off contradicts their purpose and functionality in active communication systems. Moreover, while antennas may require maintenance, this does not define their general operational status, which is more accurately described as being active when they are in use.