Final answer:
Polycythemia is a condition where there is c) an overproduction of red blood cells, often in response to chronic hypoxia. It results in elevated hematocrit and increases the viscosity of the blood, which can lead to complications like elevated blood pressure.
Step-by-step explanation:
Polycythemia is a condition characterized by an excess production of red blood cells (RBCs). This condition can be a response to chronic hypoxia, such as living at high altitudes, or can be caused by polycythemia vera, a type of bone marrow disease.
Polycythemia leads to elevated hematocrit and increased viscosity of the blood, which makes it more difficult for the heart to pump blood throughout the body and can dangerously elevate blood pressure.
The correct answer to the question "Polycythemia is a condition in which:" is (c) Excess red blood cells are produced in response to chronic hypoxia.
Options a), b), and d) are incorrect as they do not correctly describe polycythemia. Option a) discusses increased platelet production, not RBCs, option b) refers to a reduction in red blood cells which is associated with anemia, and option d) incorrectly suggests blood thinning, whereas polycythemia causes blood to become thicker.