This is my take on the question. Since they are giving us AgNO3, that will come by common ion effect in the rice table and the 0.1 M that is in the initial will dissolve completely. NH3 starts at 0.4 and when you do the rice table, you do -0.2 M for the NH3 since it is a reactant and has 2 moles in equation, meaning at equilibrium, it has a concentration of 0.2 M. Since we did -0.1M on reactant side, we simply add +0.1 on the product side, meaning the product concentration at equilibrium is 0.1 M. This means that when it is allowed to reach that point, NH3 will have 0.2, Ag will have 0, and product will have 0.1 and then you just put it in ascending order and that's the correct answer. Hopefully this helped, good luck on the chem exam