Real hard Math problem for pharmacy technician, need help.?

Aminosyn is an amino acid oftentimes used in TPM orders to provide protein for cellular repair and growth. A physician writes an order for Aminosyn 2.5% 500Ml. you look on the shelf and have only Aminosyn 8.5% 500Ml. how are you going to prepare this order using a sterile evacuated container?A add 320 ml of aminosyn 8.5% and qs with sterile water to 500Ml.B add 236 ml of aminosyn 8.5% and qs with sterile water to 500Ml.C add 124 ml of aminosyn 8.5% and qs with sterile water to 500Ml.D add 74 ml of aminosyn 8.5% and qs with sterile water to 500Ml.Plz tell me how u get it. Thx