How did multicellular organisms evolve from unicellular organisms?
A) Single-celled organisms joined together, or failed to separate after cell division.
B) Single-celled organisms joined together only.
C) Single-celled organisms failed to separate after cell division only.
D) Single-celled organisms joined together, or absorbed other species by endosymbiosis.
E) One species absorbed another species by endosymbiosis only.
