A Main Difference Between Organisms with Simple Body Plans and Those

A main difference between organisms with simple body plans and those with complex body plans is that

A) animals with simple body plans have digestive tubes with two openings,whereas organisms with complex body plans have a digestive compartment with one opening.
B) animals with simple body plans have a digestive compartment with one opening,whereas organisms with complex body plans have digestive tubes with two openings.
C) animals with simple body plans have digestive tubes with specialized compartments,whereas animals with complex body plans do not.
D) animals with simple body plans can ingest food while earlier meals are still being digested,whereas animals with complex body plans cannot.
E) animals with simple body plans eliminate undigested food via an anus,whereas animals with complex body plans eliminate undigested food via a mouth.