Choice A: Alkalosis Alkalosis occurs when the blood pH is higher than the normal range, specifically above 7.45. This condition indicates that the blood is too alkaline. Causes of alkalosis can include hyperventilation, loss of stomach acid through vomiting, or an overuse of diuretics. Since a blood pH of 7.21 is below the normal range, it does not indicate alkalosis. Choice B: Normal Blood pH The normal pH range for blood is between 7.35 and 7.45. This range is crucial for the body’s metabolic processes and enzyme functions. A blood pH of 7.21 is below this range, indicating an abnormal condition. Choice C: Acidosis Acidosis is the correct answer. It occurs when the blood pH drops below 7.35, indicating that the blood is too acidic. A pH of 7.21 is significantly below the normal range, confirming acidosis. This condition can result from various factors, including respiratory issues that lead to an accumulation of carbon dioxide or metabolic problems that increase acid production or decrease bicarbonate levels. Choice D: Hyperkalemia Hyperkalemia refers to an elevated level of potassium in the blood, not a change in blood pH. While hyperkalemia can be associated with acidosis, it is not defined by the pH level itself. Therefore, a blood pH of 7.21 does not directly indicate hyperkalemia.