The extensive phosphate deposits of Florida are the result of?

The extensive phosphate deposits of Florida are the result of? 2

(1) burial and chemical transformation of phytoplankton that lived in the shallow waters of the Florida platform

(2) phosphorous emitted by volcanoes in the Lesser Antilles island arc

(3) clams and corals found in Cretaceous carbonates deposits

(4) phosphorous emitted by the mid-Atlantic ridge

(5) phosphate deposits of Georgian and South Carolina that were eroded and re-deposited in Florida