Ms Chisholme Has Been Admitted to Hospital for an Appendicectomy

Ms Chisholme has been admitted to hospital for an appendicectomy. She has a history of a previous deep vein thrombosis, she is on an oral contraceptive pill and she smokes 20 to 25 cigarettes per day. The following seven questions relate to her management.
-Antibiotics have been ordered because her appendix was very inflamed. Stock in the ward is 1 gram of powder in a 10 ml vial for reconstitution. If the antibiotic powder displaces 0.7 ml of fluid when mixed with sterile water, the amount of water required for a
Concentration of 250 mg/ml is

A) 3.3 ml
B) 4.7 ml
C) 5 ml
D) 10 ml