Arrange the following ecosystems in increasing order of their mean NPP (tons/ha/year).
(A) Tropical deciduous forest
(B) Temperate coniferous forest
(C ) Tropical rainforest
(D) Temperate deciduous forest
A. `b lt a lt d lt c`
B. `d lt b lt a lt c `
C. `a lt c lt d lt b`
D. `b lt d lt a lt c`
