Animals that tend to have complex nervous systems are missing what?\nOptions:\n- (A) Energy\n- (B) Energy.\n- (C) nervous system\n- (D) Chlorophyll\n- (E) backbone\n- (F) alleles\n- (G) abdomen\n- (H) brain OK. Let's think hard:
User
Most invertebrates have a more complex nervous system. Invertebrates are animals without a backbone. Most animals without a backbone have a more complex nervous system.
So, the final answer is (E).
Assistant