Reasoning - photosynthetic organisms such as Algae or Plants assimilation phosphorus into their cell. Which they later transfer it to animals whom consume which then starts the cycle.
I answered the same question in another post but here I'll post what I wrote with reasoning why.
Its photosynthesis because Plants can do two important things: Use energy from the sun to turn CO2<span> (</span>carbon dioxide) and H2<span>O (water) </span>
