Communications with an emission of F1B/J2B would typically have a channel spacing of:

Correct Answer: Option A — 0.5 kHz

Emission F1B/J2B is used for Narrowband Direct Printing (NBDP) or TELEX. Due to the narrow nature of the digital signal, these emissions require very little bandwidth, typically resulting in a standard channel spacing of 0.5 kHz to ensure efficient use of the HF spectrum without causing adjacent channel interference.