It is desired to extract the soluble part from a 300 kg solid material (A + B), whose water-soluble part (A) is 35% by mass, with 50m of water. If the extraction time is 200 s for this process, determine the amount of solute (A) remaining without extraction at the end of the process. (Cs = 3 kg A/mS , k' A/b = 0.2 m/s )

A- 49,9 kg A

B- 11,2 kg A

C- 22,4 kg A

D- all extracted.