Final answer:
A Non-Directional Beacon (NDB) is a radio transmitter used in aviation for navigation purposes with a fixed frequency. It provides information about the magnetic bearing of an aircraft in relation to the beacon.
Step-by-step explanation:
A Non-Directional Beacon (NDB) is a radio transmitter used in aviation for navigation purposes. It is characterized by a fixed frequency and provides information about the magnetic bearing of an aircraft in relation to the beacon. The correct answer choice for the characteristics of an NDB is B) Frequency: Fixed, Magnetic Bearing: ADF.