An adsorption process was used to selectively remove a noxious compound A from a solution. The process contacted 200 grams of clean carbon (M) with 4 liters of solution (S) and the final value of q was 0.40 g/g. If equilibrium is given by the Langmuir isotherm with qo = 0.7 (g Alg carbon) and K = 1.125 (g/L), what was the initial concentration of A (in g/L) in the feed solution