Correct Answer: D

Rationale: Polyphagia, polyuria, and metabolic acidosis are common clinical signs of diabetes mellitus. Polyphagia refers to excessive hunger, polyuria is excessive urination, and metabolic acidosis can occur due to poorly controlled diabetes. Lower extremity edema, on the other hand, is not a typical clinical sign of diabetes mellitus. Edema in the lower extremities is more commonly associated with conditions like heart failure or kidney disease rather than diabetes mellitus.

Correct Answer: C

Rationale: When a client has early impairment of oxygen perfusion, such as in a pulmonary embolus, the nurse should expect to find restlessness, diaphoresis, tachycardia, and cool skin. Tachycardia is a compensatory mechanism to increase oxygen delivery to tissues. Cool, clammy skin (choice A) is more indicative of impaired oxygen perfusion compared to warm, dry skin. Bradycardia (choice B) is less likely to occur in the early stages and is more common in severe cases. Eupnea (choice D) refers to normal respirations in rate and depth, which may not be altered in early impairment of oxygen perfusion.

Correct Answer: C

Rationale: The correct answer is the Vastus lateralis when giving an intramuscular injection to an infant. The Vastus lateralis muscle, located in the thigh, is the preferred site for infants as it has a larger muscle mass and is well-developed, making it suitable for injections. The Ventrogluteal region and Dorsogluteal region are not recommended for infants due to their smaller muscle mass and potential risk of damaging nearby structures. The Deltoid muscle is typically used for older children and adults, not infants.

Correct Answer: C

Rationale: The correct answer is 22 gauge. A 22-gauge needle is recommended for school-age children, toddlers, and adolescents due to their muscle mass and tolerance. In infants, a smaller gauge (23-25) is preferred as their muscles are less developed and more sensitive. Choice A, 27 gauge, is too thin for an intramuscular injection in a 12-year-old boy. Choice B, 25 gauge, is more suitable for infants than for a 12-year-old. Choice D, 20 gauge, is too thick and not typically used for intramuscular injections in children.

Correct Answer: B

Rationale: The correct answer is 'enema.' Administering an enema to a client with placenta previa can dislodge the placenta, leading to an increased risk of bleeding and complications. It is crucial to avoid any interventions that may disrupt the placenta's positioning. Collecting urine and blood specimens are necessary for diagnostic purposes and monitoring, while a perineal shave is a routine procedure that does not pose a risk to the client with placenta previa.