A nurse is preparing to administer an intramuscular injection to a client. At which of the following angles should the nurse plan to insert the needle?

A. 15°: This angle is used for intradermal injections, such as a tuberculin skin test, where the medication is deposited just under the epidermis. It would not allow the needle to reach the muscle layer, making it inappropriate for intramuscular administration. B. 60°: An angle of 60° is not a standard technique for any specific injection type. At this angle, the medication would likely end up in the subcutaneous tissue instead of the muscle, leading to improper absorption and reduced effectiveness. C. 45°: This angle is appropriate for subcutaneous injections, such as insulin, when a shorter needle is used or in thin clients. It does not penetrate deeply enough to reach the muscle tissue for intramuscular medication administration. D. 90°: A 90° angle ensures the needle penetrates through the subcutaneous tissue and into the muscle, which is necessary for intramuscular injections. This angle allows the medication to be deposited directly into the muscle for proper absorption and therapeutic effect.