The correct answer is B: An end-fed half-wavelength dipole. A Zepp antenna is an end-fed half-wavelength dipole. The name comes from its use on Zeppelin airships, where one end was fed and the other end was free. A Zepp antenna is essentially a half-wave dipole fed at one end instead of the center. One end connects to the feed line, and the other end is left open (not connected). This creates a different current distribution and impedance compared to a center-fed dipole. The end-fed configuration was convenient on airships where the antenna could hang from the ship. Zepp antennas typically require a matching network or tuner because the end-fed configuration creates different impedance than center-fed dipoles.