What is a defining feature of an active volcanic island arc?

An active volcanic island arc is characterized primarily by a series of volcanoes formed at convergent plate boundaries, specifically along subduction zones. In a subduction zone, an oceanic plate sinks beneath another tectonic plate, leading to the melting of mantle material and magma formation. This magma rises to the surface, resulting in volcanic activity, often creating an explosive volcanic arc that emerges from the ocean.

The volcanic islands are typically arranged in a linear fashion parallel to the trench created by the subducting plate. This geological process is a direct result of the interaction between tectonic plates, making the presence of multiple active volcanoes a defining feature of active volcanic island arcs. Such arcs can be found in locations like the Aleutian Islands in Alaska and the islands of Japan, where significant seismic and volcanic activity is evident.

In contrast, the other choices do not align with the definition of an active volcanic island arc. Flat plains, meteor craters, or uplifted mountain ranges do not specifically represent the volcanic activity or geological processes associated with subduction zones, making them incorrect in this context.