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