Correct Answer: A

Rationale: The correct action is to apply the nitroglycerin ointment to a hairless area of the client's chest, back, or upper arms. This allows for better absorption of the medication. Choice B is incorrect because rubbing the ointment gently into the skin may be appropriate, but the primary action is to ensure application on a hairless area. Choice C is incorrect as covering the ointment with a transparent dressing is not a standard practice for nitroglycerin ointment administration. Choice D is incorrect because massaging the ointment into the skin is not recommended, as it can alter absorption rates.

Correct Answer: D

Rationale: Intramuscular injections in the ventrogluteal site should be administered at a 90-degree angle. This angle ensures that the medication reaches the muscle tissue effectively. Angles less than 90 degrees can cause subcutaneous injection instead of intramuscular, leading to slower absorption of the medication. Angles greater than 90 degrees risk hitting bone or nerves, causing unnecessary pain or injury. Therefore, the correct angle for administering intramuscular injections in the ventrogluteal site is 90 degrees.

Correct Answer: A

Rationale: The correct answer is A because isosorbide mononitrate is used for long-term prophylaxis against anginal attacks. Choice B is incorrect because isosorbide mononitrate should not be crushed. Choice C does not specify a particular time for medication administration. Choice D is incorrect because isosorbide mononitrate is not meant to be taken as needed for chest pain; it is part of a long-term therapy plan.

Correct Answer: D

Rationale: The correct answer is D: Hearing acuity. Gentamicin is known to be ototoxic, which means it can cause damage to the auditory system leading to hearing loss. Monitoring hearing acuity is crucial to detect early signs of hearing impairment. Monitoring urinary output (choice A) is important for assessing kidney function but is not directly related to gentamicin's adverse effects. Monitoring serum glucose (choice B) and respiratory rate (choice C) are not specifically associated with gentamicin therapy.

Correct Answer: B

Rationale: The correct answer is B: Osteoporosis. Osteoporosis is a concern with levothyroxine as it can increase the risk for fractures, particularly in older adults. Levothyroxine treatment can exacerbate bone loss in individuals with osteoporosis. Choices A, C, and D are not directly contraindicated with levothyroxine therapy for hypothyroidism.