I would like to know the reasons behind the answer.
Why is it Possible/Not Possible for each case?
The potential intersections of various catabolic and anabolic pathways through common metabolic intermediates and products are shown below. For the compounds given below, being produced from each other in the order given, indicate whether that intersection of pathways is possible (P) or not possible (NP), to make large amounts of the end product shown. Assume that the compounds shown are being broken down by only one catabolic pathway and synthesized by only one anabolic pathway, with no intervening pathways.
