Final answer:
The Nervous System, specifically the somatic nervous system, controls our deliberate actions by allowing us to voluntarily move our skeletal muscles according to the signals sent from the cerebral cortex.
Step-by-step explanation:
The system that controls our deliberate action is A) the Nervous System. The voluntary control of our muscles and movements, which are considered deliberate actions, is governed by the somatic nervous system, a part of the overall nervous system. The somatic nervous system interfaces with the skeletal muscles to facilitate voluntary movement, which involves a conscious decision to perform a specific action. This coordination is accomplished via the cerebral cortex, which sends signals to the effectors - the muscles that enact the movements.