Which of these units of Red Blood cells, that has been issued and returned to the blood bank, can be returned to inventory and is acceptable to use?
A) a unit of RBCs that was issued 1 hour previously but not transfused and kept at room temperature
B) a unit of RBCs that was not transfused but stored in a temperature-controlled remote refrigerator in the operating room for 2 hours
C) a unit of RBCs that was issued 15 minutes previously, but returned unused with one of the sterile ports opened
D) a unit of RBCs that was issued to the ER with other units in a temperature controlled blood bank emergency cooler, returned to the blood bak 5 hours after issue, with internal temperature of the system reading 15C