Correct Answer: D

Rationale: Dehydration can result from significant fluid loss due to vomiting, diarrhea, or inadequate fluid intake. Prolonged vomiting and diarrhea lead to excessive fluid loss from the body, contributing to dehydration. Similarly, not consuming enough fluids can also result in dehydration. Choice A and B are too specific as they only mention one cause each, while choice C is also correct but does not encompass all the potential causes of dehydration as mentioned in choice D.

Correct Answer: D

Rationale: A low pH indicates acidosis (normal pH is 7.35 to 7.45). The PaCO2 is also low, which causes alkalosis. The bicarbonate is low, which causes acidosis. The pH bicarbonate more closely corresponds with a decrease in pH, making the metabolic component the primary problem. Therefore, the correct interpretation of the arterial blood gas results is metabolic acidosis with a compensatory respiratory alkalosis. Choices A, B, and C are incorrect because they do not accurately reflect the primary acid-base disturbance and the compensatory response seen in the given results.

Correct Answer: D

Rationale: The correct answer is 'Electrolyte.' Electrolytes are substances that dissociate into ions when dissolved in water. Intracellular fluid, interstitial fluid, and plasma are not substances that dissociate into ions in a water solution. Intracellular fluid is the fluid inside cells, interstitial fluid is the fluid between cells, and plasma is the liquid component of blood. These choices do not dissociate into ions in a water solution, unlike electrolytes.

Correct Answer: C

Rationale: The correct answer is C: 'plasma and interstitial fluid.' Extracellular fluid consists of all body fluids outside the cells, primarily including plasma (the liquid component of blood) and interstitial fluid (the fluid between cells). Choices A, B, and D are incorrect because intracellular fluid is located within the cells, not in the extracellular fluid compartment.

Correct Answer: C

Rationale: The correct answer is C: hypernatremia. Hypernatremia refers to an elevated level of sodium in the blood, specifically when it is more than 145 mEq/L. Choice A, hyponatremia, is incorrect as it refers to low sodium levels. Choice B, hyperkalemia, is incorrect as it refers to high potassium levels, not sodium. Choice D, hypercalcemia, is also incorrect as it relates to elevated calcium levels, not sodium.