Final answer:
The correct answer is option d. In a spun microhematocrit tube, red-tinged plasma indicates the hemolysis of erythrocytes, meaning that hemoglobin has been released into the plasma. Therefore, the correct answer is d. hemolyzed.
Step-by-step explanation:
When a spun microhematocrit tube shows plasma that has a red tinge, it indicates that the red blood cells (RBCs) have been hemolyzed. Hemolysis is the destruction (lysis) of erythrocytes and the release of their hemoglobin into circulation. This occurrence is distinct from polycythemia, which is an elevated level of hemoglobin or RBCs that may result from various conditions, including polycythemia vera, dehydration, or living at high altitudes.
The correct term for the red-tinged plasma observation is hemolyzed, which refers to the presence of hemoglobin released into the plasma due to the rupture of erythrocytes. Thus, the answer to the student's question is d. hemolyzed.