What kind of markings are used to indicate the taxiway centerline?

Answer: B — single solid yellow line

A single solid yellow line is used to indicate the taxiway centerline on airfields. This marking plays a crucial role in guiding pilots and ground personnel along taxiways, ensuring safe and efficient movement of aircraft on the ground. The yellow color signifies that this is a taxiway, as opposed to other markings which might represent runways or other operational areas. These centerline markings help pilots maintain proper orientation and alignment while taxiing, especially in low visibility conditions or crowded airfield situations. The clarity of a single solid yellow line ensures that its purpose as a taxiway guide is easily recognizable, promoting safety and reducing the likelihood of runway incursions or taxiing errors.