Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Y-shaped or 2-channel energy flow model of E.P. Odum is more realistic than linear energy flow model of Lindeman. Reason R: Y-shaped model is realistic because it has both grazing and detritus food chains. In the light of the above statements, choose the most appropriate answer from the options given below: