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
Please answer the following question by reasoning step-by-step.
(E)
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 answer is (E)