Which statement best explains why scientists depend on submersibles to study ocean features?

a. the extreme pressure and freezing temperatures of the deep ocean make it dangerous to send humans to the greatest ocean depths.

b. the vastness of the ocean environment makes it difficult for any single ship to collect enough data to produce accurate maps.

c. signals used to collect remote sensing data cannot travel through ocean water.

d. the greater salinity of surface waters corrodes metals used to construct ocean vessels.