Which system includes the altimeter and vertical speed indicator?

The altimeter and vertical speed indicator are both components of the Pitot Static System. This system is critical in determining an aircraft's altitude and rate of climb or descent. The altimeter measures the aircraft's altitude by comparing the atmospheric pressure outside the aircraft to a pre-measured standard pressure. This instrument works off the static pressure input, which is derived from the static ports located on the airframe.

Similarly, the vertical speed indicator (VSI) operates on the principle of static pressure changes. It measures the rate of climb or descent by detecting the rate at which ambient pressure changes, thus giving pilots essential information about the aircraft's vertical movement relative to the surrounding air.

The other systems listed—such as the electrical system, hydraulic system, and fuel system—serve different functions and contain different components that do not include the altimeter or VSI. The electrical system powers cockpit instruments and provides electrical power to systems; the hydraulic system is responsible for operating controls like flaps and landing gear; and the fuel system manages fuel delivery to the engines. Therefore, all these other systems do not incorporate the specific functions associated with the altimeter and vertical speed indicator, affirming the Pitot Static System as the correct answer.