If You Were Studying the Sediments Along the Beach and Narrow

Multiple Choice

If you were studying the sediments along the beach and narrow continental shelf here,how could you tell that the river once flowed from the volcanoes straight out to the coast,instead of flowing somewhere inland as it does now?

A) Look for mineral and rock clasts of volcanic origin in the newest sediments of the beach and continental shelf
B) Look for volcanic ash
C) Look for mineral and rock clasts of volcanic origin in the older sediments of the beach and continental shelf
D) Both a and b are correct.