What part of the brain controls complex behaviors, processes information, and make decisions?

The correct answer is: cerebral cortex (prefrontal).

Cerebral cortex is the outer layer of cerebrum and it is the neural integration area of the brain. Globally, the role of cerebral cortex is role in memory, attention, perception, awareness, thought, language, and consciousness.

Prefrontal cortex is part of the cerebral cortex (cover the front part of frontal lobe). It is involved in complex social behavior of the human, complex cognitive behavior, decision making.