Explanation: A Hertzian antenna is a fundamental type of dipole antenna, commonly designed as a half-wave radiator. For an antenna to efficiently radiate or receive a signal at a specific frequency, its physical length is typically designed to be a resonant fraction of the signal's wavelength. For a half-wave dipole, the physical length of the antenna is approximately one-half (1/2) of the free-space wavelength of the signal it transmits or receives. Therefore, if the physical length of the antenna is 'L', and the radiated wavelength is 'λ', then L ≈ λ/2. Rearranging this relationship shows that the radiated wavelength (λ) is approximately twice the physical length of the antenna (λ ≈ 2L). Options A and B are incorrect because the length of the coaxial cable or RF line (feedline) does not directly determine the radiated wavelength of the antenna element itself. Option C is incorrect; if the radiated wavelength were 1/2 the physical length, it would imply the antenna's physical length is twice the wavelength, which is not characteristic of a resonant half-wave Hertzian antenna.