Answer:
The correct answer is A. The seamounts that formed the Hawaiian Islands were underwater volcanoes.
Step-by-step explanation:
All Hawaiian islands are of volcanic origin. They were caused due to the shift of tectonic plates beneath the Pacific Ocean toward the northwest, that caused the formation of many volcanoes. Currenlty, the hot spot does not shift and slowly creates new volcanoes. Due to the location of the hot spot, the only active volcanoes are located in the southern half of the Big Island.