Explanation: The fundamental relationship between wavelength (λ), frequency (f), and the speed of light (c) is λ = c/f. Radio waves travel at the speed of light, which is approximately 300,000,000 meters per second in a vacuum. * **Option B** correctly applies this foundational formula: Wavelength (in meters) = 300,000,000 meters/second / Frequency (in Hertz). This is the most direct expression. * **Option A** is a simplified form derived by adjusting the units. If frequency is given in kilohertz (kHz), which is 1,000 Hz, then 300,000,000 / (f_kHz * 1,000) simplifies to 300,000 / f_kHz. This yields wavelength in meters. * **Option C** similarly adjusts for megahertz (MHz). If frequency is in MHz, which is 1,000,000 Hz, then 300,000,000 / (f_MHz * 1,000,000) simplifies to 300 / f_MHz. This also yields wavelength in meters. All three formulas are mathematically equivalent, representing the same physical principle, but are expressed with different constants for convenience based on the units of frequency used (Hz, kHz, or MHz). Therefore, all are correct.