Correct Answer: B

Rationale: The purpose of the cuff in a Tracheostomy tube is to separate the trachea from the esophagus. The cuff helps prevent aspiration by creating a seal that separates the trachea from the esophagus, reducing the risk of food or fluids entering the lungs. Choices A, C, and D are incorrect because the cuff's primary function in a Tracheostomy tube is to prevent aspiration rather than separating the upper and lower airway, larynx from the nasopharynx, or securing the placement of the tube.

Correct Answer: C

Rationale: The correct answer is C: Bone pain. Vitamin D deficiency often leads to bone pain and weakness as it plays a crucial role in maintaining bone health by aiding in the absorption of calcium. Hair loss (choice A) is not a common symptom of vitamin D deficiency. Night blindness (choice B) is typically associated with vitamin A deficiency, not vitamin D deficiency. Rashes (choice D) are not a common symptom of vitamin D deficiency.

Correct Answer: A

Rationale: The correct answer is 'A: case study.' A case study involves an in-depth examination of a single individual, group, or event. In this scenario, focusing on one boy aligns with the definition of a case study. The other options are not applicable: B) A longitudinal study involves following subjects over a period of time, C) A cross-sectional study examines a population at a single point in time, and D) An evaluative study assesses the effectiveness of a program or intervention, which is not the focus of the given scenario.

Correct Answer: D

Rationale: When determining priorities in patient care, assessing perfusion, respiration, and locomotion are crucial. However, assessing mentation is also important but not typically included in the ABCs of emergency care. Monitoring mentation is essential for neurological assessment and detecting changes in mental status, but it is not part of the immediate priorities in life-threatening situations.

Correct Answer: A

Rationale: During the Emergent phase of burns, the most fatal electrolyte imbalance is Hypokalemia. This is due to the shift of potassium from the intracellular space to the extracellular space, leading to low potassium levels in the blood. Choices B, C, and D are incorrect because Hyperkalemia, Hypernatremia, and Hyponatremia are not typically associated with the Emergent phase of burns and do not pose the same level of risk as Hypokalemia in this context.