A Nurse Is Conducting a Class on How to Self-Manage

A nurse is conducting a class on how to self-manage insulin regimens. A patient asks how long a vial of insulin can be stored at room temperature before it goes bad. What would be the nurses best answer?

A) If you are going to use up the vial within 1 month it can be kept at room temperature.
B) If a vial of insulin will be used up within 21 days, it may be kept at room temperature.
C) If a vial of insulin will be used up within 2 weeks, it may be kept at room temperature.
D) If a vial of insulin will be used up within 1 week, it may be kept at room temperature.