Concept:A crater lake forms when water collects in a hollow at the top of a volcano.Explanation:Crater lakes are found in the circular depression left at the summit of a volcano after an eruption.Such lakes are common where volcanic activity has stopped completely, so the crater is no longer filled with lava.These areas are described as having extinct volcanoes because the volcano no longer erupts.While active volcanoes may sometimes hold water in their craters, crater lakes are more usually linked with extinct volcanic areas.Answer:C. that have extinct volcanoes