What is the deep scattering layer (DSL)?
a. The DSL is a dense aggregate of animals that migrate up and down in synchrony with daylight.
b. The DSL is the lowest photosynthetic layer.
c. The DSL is a hydrothermal vent community.
d. The DSL is a dense aggregate of microscopic primary consumers.
e. The DSL is a bathypelagic zone.
Answer: A