Final answer:
Insulin is usually given by the subcutaneous route, which involves injecting it into the fatty tissue just below the skin.
Step-by-step explanation:
The correct answer is option b. SC, which stands for subcutaneous. Insulin is usually given through subcutaneous injections, which means injecting it into the fatty tissue just below the skin. This route allows for slow and consistent absorption of insulin into the bloodstream, mimicking the body's natural release of insulin.