A client is prescribed a short-acting insulin to help treat her type 1 diabetes. What important note would the pharmacist most likely give the client regarding insulin?

A. Once opened, a vial with insulin is good for only 24 hours at room temperature.
B. Administer the insulin via an insulin needle only.
C. Insulins should never be administered via injection into veins.
D. Never store insulins in the refrigerator.