Right option is (b) Food chain
Explanation: In a food chain, the harmful toxic compounds get accumulated within the first organism in a trophic level, it is usually the first organism, the Xenoestrogen is a hormone that have similar functions to natural endogenic estrogen produced by the body of an organism but are chemically different and synthetically administered, Gypsum is the by product of the certain acids like Citric acid, whereas, the byproduct i.e. gypsum is used fro sodic soil reclamation.