Question id 85 - Flight Planning and Monitoring - ATPL - Airline Transport Pilot license

Flight Planning and Monitoring - Item 9 of the ATC flight plan includes 'NUMBER AND TYPE OF AIRCRAFT'. In this case 'NUMBER' means:
The registration number of the aircraft
The number of aircraft which will separately be using a repetitive flight plan (RPL)
The number of aircraft flying in a group
The ICAO type designator number as set out in ICAO Doc 8643

Training tests and timed exam simulations ATPL - Airline Transport Pilot license