They could have kidney failure maybe worse
Hydrochloric acid is a strong acid (fully dissociates when dissolved in water due to the polar covalent bond)
It is a very stable molecule
It is highly reactive with metals and with oxidising agents such as organic materials, alkalis, water etc.
Can be extremely corrosive if solution is concentrated.
It is C because it’s all in the middle of the brain
Irreversible nerve damage can be caused by a deficiency of the vitamin B-12 or an excess of the vitamin B-6.