Statement-1: Reflex arcs have evolved in animals because the thinking process of the brain is not fast enough.
Statement-2: All involuntary actions are reflexes but all reflexes are not involuntary.
Statement-3: Reflex arcs continue to be more efficient for quick responses even after complex neuron networks have come into existence.

The correct option is D All statements are correct
Reflex action is an automatic response to a stimulus that is not under the voluntary control of the brain. Hence, it is described as an involuntary action. The path followed by an impulse in a reflex action is called reflex arc. Reflex arc has evolved in animals because the thinking process of the brain is not fast enough and they continue to be more efficient for quick responses.