There are a couple of ways in which you can express the concentration of a solution, and here they are: gram per liter (g/L), molarity (M), parts per million (ppm.), and percents (%).
As you can see, only M appears in your answers, which means that the correct option should be (2) 3.5 M.
The answer is C2O.............
If its sodium it would have 11 electrons
NH3 has a Molar mass of 17g
3.47 * M(NH3) = 58.99g of NH3 in the cleaning agent