Answer:
Nervous System
Explanation:
The fact that the injury "damaged nerves" suggests that there was direct injury to the nervous system, which is directly causing Kai's pain & numbness.
The nervous system (in a general sense) is made up of the brain, spinal cord, and all nerves that send and receive signals to and from every part of the body. Damage to sensory nerves can cause pain, tingling, and numbness.
