A nurse is preparing to administer 12 units of regular insulin and 8 units of NPH insulin to a patient. What is the correct method to prepare this mixture?

Use two separate syringes for each type of insulin to avoid errors.

Mix both insulins together in the vial before drawing up the dose.

Withdraw 8 units of NPH insulin first, then 12 units of regular insulin into the same syringe.

Withdraw 12 units of regular insulin first, then 8 units of NPH insulin into the same syringe.