When selecting an RTTY transmitting frequency, what minimum frequency separation from a contact in progress should you allow (centre to centre) to minimize interference?

Radioteletype (RTTY) is a narrowband digital mode. A typical amateur RTTY signal uses a 170 Hz shift and operates at 45.45 baud, resulting in a total bandwidth of around 250 to 300 Hz. To avoid interfering with an ongoing RTTY QSO, you must leave enough room for your signal's bandwidth. Therefore, a centre-to-centre frequency separation of 250 Hz to 500 Hz provides a safe buffer so the adjacent signals do not overlap. Other options are incorrect because 3 kHz to 5 kHz is the appropriate spacing for wider voice modes like Single Sideband (SSB), while 50 Hz to 100 Hz is far too narrow and will result in overlapping signals and severe interference.