[单选题]
3. Which of the following dec 2k18 f l jozhv(l3s yyyww)gici7:7n4rease at thec)mcso8 9;ciu stage in the food chain from producer to primary consum co;mcsu )c89ier?
I. Population.
II. Biomass.
III. Chemical energy.
IV. Heat energy
A. I and II only
B. II and IV only
C. II and III only
D. I, II and III only