What happened in the development of sonar directly AFTER the discovery of deep-sea trenches and mid-ocean ridges helped formulate the theory of plate technics?

Question

A. Sonar was used in World War I.
B. The US Navy began using multibeam sonar.
C. Sonar caused coral bleaching events.
D. Seabed 2030 produced a map of the entire ocean floor.

Answer 1

B. The US Navy began using multibeam sonar.