The correct answer is option 3 i.e.Control of reflex actions
The spinal cord is a part of the Central Nervous System whose main function is to control reflex actions.
A Reflex action is a way for the body to automatically and rapidly respond to a stimulus to minimise any further damage to the body.
It follows this general sequence and does not involve the brain: stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector→ response.
A reflex is made possible by neural pathways called reflex arcs
which can act on an impulse before that impulse reaches the brain.
Some examples are - if we unknowingly touch a hot plate, we immediately move our hand away from it
Other examples are knee jerk, coughing, yawning, sneezing, etc.