Look at the last three positions first: water must travel Main Line then Lateral then Drippers, since a main line always feeds sub units before the crop level laterals and drippers. Option 1 ends with Fine Filter then Drippers, which is wrong because filtration must happen near the pump, not just before the emitters. Option 3 places the Lateral (C) right after the Pump, which cannot be right since laterals are the last small pipes near the plants, not the first fitting after the pump. Option 4 places the Main Line right after the pump and the filters at the very end, which is backward because unfiltered water would clog the drippers. Only option 2, Pump - Course Filter - Fine Filter - Fertilizer Tank - Main Line - Lateral - Drippers, keeps filtration early and ends Main Line - Lateral - Drippers in the correct physical order. \[\boxed{\text{Option 2}}\]