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. Seabed 2030 produced a map of the entire ocean floor.
D. Sonar caused coral bleaching events.

Answer 1

B. The US Navy began using multibeam sonar.