Which of the following instruments would normally feature range markings?

The correct answer highlights instruments that require range markings to provide critical operational information to the pilot. In aviation, range markings are essential for indicating safe operational limits.

Airspeed indicators typically feature markings to indicate various speed ranges, such as stall speed, maneuvering speed, and maximum speed, which help pilots understand their performance envelope. The cylinder head temperature gauge also has range markings, as it indicates the temperature limits for safe engine operation. These markings allow pilots to easily assess whether the temperatures are within safe limits during various phases of flight.

The remaining instruments in the other choices do not commonly feature range markings that are as crucial for flight operations. For example, oil pressure gauges primarily indicate whether pressure is within an acceptable range, but they might not have dynamic range markings like airspeed indicators. Similarly, vertical speed indicators and heading indicators provide critical data, yet they function without the need for explicit range markings as required by the airspeed indicator and cylinder head temperature gauge.