It Is Generally Thought That Animals Have Undergone Four Major

It is generally thought that animals have undergone four major physiological and anatomical innovations during their evolution. These are (in no particular order)

A) multicellularity, bilateral symmetry, origin of patterns of embryonic development, development of tissues.
B) development of the versatile forelimb, multicellularity, origin of patterns of embryonic development, development of tissues.
C) development of tissues, photosynthesis, bilateral symmetry, multicellularity.
D) bilateral symmetry, development of tissues, origin of the multichambered heart, origin of patterns of embryonic development.
E) origin of patterns of embryonic development, development of the versatile forelimb, origin of the multichambered heart, multicellularity.