Final answer:
The long-acting type of insulin referred to in the question is Glargine (Lantus). This form of insulin provides a steady level of insulin and is often used once or twice daily.
Step-by-step explanation:
The type of insulin that is long-acting is d. Glargine (Lantus). Long-acting insulins are designed to be injected once or twice daily to provide a consistent level of insulin in the bloodstream throughout the day and night. Other types of insulin, such as Lispro (Humalog) and Regular insulin (Humulin R) are rapid-acting and short-acting respectively, and NPH (Humulin N), which is intermediate-acting.
Insulin is important in the metabolism of glucose and helps maintain normal blood glucose levels. In the case of recombinant insulin production, it is a recombinant protein created through molecular cloning. This insulin is designed to mimic the body's natural insulin and is usually considered identical to human insulin produced in the pancreas.