$\begin{array}{1 1}(a)\;Plankton\rightarrow Submerged\rightarrow Free floating \rightarrow Reed swamp\rightarrow Marsh meadow\rightarrow Scrub stage\rightarrow Forest\\(b)\;Plankton\rightarrow Reed swamp\rightarrow Marsh meadow \rightarrow Submerged\rightarrow Free floating\rightarrow Scrub stage\rightarrow Forest\\(c)\;Plankton\rightarrow Free floating\rightarrow Submerged \rightarrow Reed swamp\rightarrow Marsh meadow\rightarrow Scrub stage\rightarrow Forest\\(d)\;Plankton\rightarrow Free floating\rightarrow Submerged \rightarrow Reed swamp\rightarrow Scrub stage\rightarrow Marsh meadow \rightarrow Forest\end{array} $
