If a Researcher Is Looking for a Study Organism That

Multiple Choice

If a researcher is looking for a study organism that possesses a circulatory system, they should choose a

A) small, flat aquatic animal.
B) small, sedentary aquatic animal with a highly branched central cavity.
C) large, active, terrestrial animal.
D) very small, multicellular animal with short diffusion distances.
E) single-celled organism.