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.
-On her return to the ward later in the day, she is ordered 7500 units of Heparin. Stock available in the ward is 5000 units/0.2 ml. The volume of this medication required for this order is

A) 1 ml
B) 0.9 ml
C) 0.6 ml
D) 0.3 ml