A) it would not be able to obtain food.
B) it would have difficulty with buoyancy.
C) it would have difficulty with osmoregulation.
D) it would not experience the temperature stability found in the oceans.
E) it would not be able to obtain oxygen due to the absence of waves in the water.

A) The ocean water provided buoyancy.
B) They did not require a skeleton for support.
C) Internal fluid and salt balance were easy to maintain.
D) Reproduction was independent of internal fertilization.
E) The changeable temperature facilitated natural selection.

A) Cnidaria
B) Porifera
C) Annelida
D) Ctenophora
E) Echinodermata