$\text{P}_4+3\text{OH}^-+3\text{H}_2\text{O}\xrightarrow{ \ \ \ \ \ \ \ }\text{PH}_3+3\text{H}_2\text{PO}^-_2$
- APhosphorus is undergoing reduction only.
- BPhosphorus is undergoing oxidation only.
- CPhosphorus is undergoing oxidation as well as reduction.
- DHydrogen is undergoing neither oxidation nor reduction.
