Consider the following statements related to nitrification process:
- Electron acceptor type vary depending on whether nitrosomonas or nitrobacter is involved.
- Predominant carbon source is organic matter.
- Predominant carbon source is inorganic carbon.
- Electron donor during conversion of ammonium ions to nitrite ions is ammonium ions.
Choose the correct option(s) from the following
- $(iii)$ and $(iv)$ are correct
- $(i)$ and $(ii)$ are correct
- $(i)$ is incorrect and $(iii)$ is correct
- $(ii)$ is correct and $(iii)$ is incorrect
