Sri Lanka Broadcasting Corporation broadcasts its programmes on the 25 metre band. Which one of the following is the frequency of broadcasting?

The frequency of a radio wave is inversely proportional to its wavelength, calculated using the formula f = c / λ, where 'c' is the speed of light (approximately 300,000,000 m/s) and 'λ' is the wavelength [t6][t7]. For the 25-metre band, the calculation (300 / 25) yields a frequency of approximately 12 MHz. Standard frequency allocation tables confirm that the 25-metre broadcasting band typically spans from 11,650 kHz to 11,975 kHz [t1]. This range is commonly referred to in shortwave listening as the 12 MHz band [t2]. Other options provided, such as 16 KHz or 2.2 KHz, fall into the Very Low Frequency (VLF) range, while 90 MHz belongs to the VHF (FM) band, making 12 MHz the only correct frequency corresponding to the 25-metre shortwave band used by international broadcasters like the Sri Lanka Broadcasting Corporation.