Which series represents the correct ranking of average NPP,from greatest to smallest?

A) Marsh $\rightarrow$ river $\rightarrow$ estuary
B) Marsh $\rightarrow$ estuary $\rightarrow$ river
C) Estuary $\rightarrow$ marsh $\rightarrow$ river
D) Estuary $\rightarrow$ river $\rightarrow$ marsh
E) River $\rightarrow$ estuary $\rightarrow$ marsh