Evolutionary adaptations that help diverse animals directly exchange matter between cells and the environment include
A) a gastrovascular activity, a two-layered body, and a torpedo-like body shape.
B) an external respiratory surface, a small body size, and a two-cell-layered body.
C) a large body volume; a long, tubular body; and a set of wings.
D) complex internal structures, a small body size, and a large surface area.
E) an unbranched internal surface, a small body size, and thick covering.
Answer: B