Ecological Pyramid

Which of these is/are limitation/s of ecological pyramids? I. Decomposers are not given any place in ecological pyramids. II. Ecological pyramids do not accommodate a food web. III. Ecological pyramids may be upright or inverted. IV. They don't consider omnivores in two different trophic levels.

(A) The amount of living matter (biomass) present at every trophical level is called standing crop (B) Saprophytes are not given any place in ecological pyramids (C ) Ecological pyramid does not account for the same species belonging to two or more trophic levels

There are certain limitations of ecological pyramids correct option :- (A) It assumes a simple food chain (B) Saprophytes are not given any place in ecological pyramids. (C) It does not take into account the same species belonging to two or more trophic levels

Which of the following scientists proposed the concept of ecological food pyramid ?