Which abbreviation indicates a route of administration that is subcutaneous?

The abbreviation that indicates a subcutaneous route of administration is 'sc,' which stands for 'subcutaneously.' This method involves injecting medication into the fatty tissue layer beneath the skin, allowing for slow and steady absorption of the medication into the bloodstream. It is commonly used for insulin administration and for drugs that require a slower onset of action.

Other choices do not relate to subcutaneous administration. For example, 'sl' stands for 'sublingual,' which involves placing a drug under the tongue for absorption. 'ac' means 'before meals,' which indicates timing rather than a route of administration. Lastly, 'prn' stands for 'as needed,' describing the frequency of administration without specifying how the medication is given. Hence, sc is the clear choice for recognizing the subcutaneous route.