The normal landing gear extension/retraction system extends gear and all gear doors.

• A. Extend and retract gear and retract doors only
• B. Extend and retract gear and all gear doors
• C. Extend and retract gear and extend doors only
• D. Operates as a backup to the primary system

Answer: (B)

The normal landing gear extension/retraction system moves not only the wheels but also the doors that cover the gear wells. When extending, the doors open to allow the gear to drop out; when retracting, the doors close to seal the bays. This coordinated action keeps the aircraft aerodynamically clean and protects the gear when it’s tucked away. So the system extends and retracts both the gear and all gear doors. The other options don’t fit because they imply only the gear or only the doors move, or they describe a backup function rather than the normal operation.