What must be present for landing options to be authorized on a runway where a/c is taxiing?

The presence of a safety logic system is crucial for authorizing landing options on a runway where an aircraft is taxiing. This system is designed to ensure that the operational environment is safe for both the arriving aircraft and the taxiing aircraft. The safety logic system monitors multiple factors, including aircraft positions, their speeds, and potential conflicts, enabling air traffic control to make informed decisions and maintain safety during operations.

Without such a safety system in place, the risk of an accident increases significantly, as the air traffic controllers would not have the necessary oversight on the movements of both the landing and taxiing aircraft. Other options, although important in various contexts, do not provide the same level of assurance for maintaining safety during the critical phase of landing while another aircraft is taxiing on the same runway.