The correct answer is C. Polycythemia.
Polycythemia is a condition in which the body produces too many red blood cells. This can lead to a number of health problems, including blood clots, heart disease, and stroke.
Anemia is a condition in which the body does not have enough red blood cells. This can lead to a number of symptoms, including fatigue, shortness of breath, and pale skin.
Haemophilia is a bleeding disorder that is caused by a deficiency of one of the clotting factors. This can lead to excessive bleeding from even minor injuries.
Leukaemia is a type of cancer that affects the white blood cells. This can lead to a number of symptoms, including fatigue, fever, and weight loss.
In conclusion, the correct answer is C. Polycythemia.