As a result of adaptive radiation, there are more than 50 species of honeycreeper birds found on the Hawaiian Islands. These species differ in their beak shapes, food sources, and feeding behaviors. Which of the following statements best explains how adaptive radiation could have led to the diversity of honeycreeper species found on the Hawaiian Islands?

A. Over time, many closely related honeycreeper species migrated to the islands from the mainland. Each species settled into the ecological niche it was best adapted for B. A period of volcanic activity reduced the ecological diversity of the Islands, which increased competition between honeycreeper populations and led to the formation of new species.
C. Members of a single bird species came to the islands from the mainland. Over time, this species diverged into many species as groups of birds adapted to different habitat niches on the islands
D. An increased mutation rate among island bird populations led to the accumulation of prezygotic reproductive barriers over time. These barriers then led to a high rate of speciation on the islands.​