Answer:
Opion 4. The hydrogen in HCl reduce from proton to hydrogen gas (H at ground state)
Explanation:
The reaction is: Mn + HCl → MnCl₂ + H₂
Magnessium changed the oxidation state from 0 to +2
It has increased, so it was oxidized
H changed the oxidation state from +1 to 0
It has decreased, so it was reducted.