The conventional landing gear arrangement includes which of the following?

The correct choice refers to a conventional landing gear arrangement, often called tailwheel configuration. This setup typically features two main wheels located at the front of the aircraft and a smaller third wheel (tailwheel) located under the tail. This design allows for stability during takeoff and landing, especially when the aircraft is on the ground. The tailwheel configuration also offers certain advantages in terms of visibility for the pilot during ground operations and is commonly seen in older aircraft designs.

In contrast, a third wheel under the nose generally signifies a nosewheel design, which is characteristic of tricycle landing gear, not a conventional setup. Similarly, a wheel arrangement with skids is associated with aircraft that do not use wheels for landing gear, such as some helicopters or skiplanes. Lastly, a single wheel configuration does not accurately describe conventional landing gear, which relies on a minimum of three wheels for balanced support and stability during landing and taxi on various terrains.