In an ecosystem,

(A) cycling of energy and nutrients is a coupled process.
(B) cycling of energy is an independent process.
(C) movement of energy is unidirectional.
(D) both macro and micro consumers are necessary.

Choose the correct option for statement/s which complete/s the above statement.

In an ecosystem cycling of energy and nutrient is a coupled process, which occurs simultaneously. Movement of energy is always unidirectional and occurs from producers to consumers. An ecosystem may function without macro-consumer but producer and micro-consumer or decomposers are necessary for its functioning.