Select the mismatched pair in the following and correct it.
(a) Biomagnification: Accumulation of chemicals at the successive trophic levels of a food chain.
(b) Ecosystem: Biotic component of environment.
(c) Aquarium: A man-made ecosystem.
(d) Parasites: Organisms which obtain food from other living organisms.
(b) Ecosystem: It is an ecological system consisting of a distinct biotic community and the physical environment (consisting of a number of abiotic factors) both interacting and exchanging materials between them.