One Symptom of Sickle Cell Disease Is Anemia Which Causes

One symptom of sickle cell disease is anemia which causes shortness of breath, among other things. How does sickle cell disease cause shortness of breath?

A) The deformed red blood cells cannot carry sufficient oxygen through the body so the person has to breathe harder, trying to get more oxygen.
B) The disease is frightening, causing stress and harder breathing.
C) Muscles cannot effectively absorb the deformed red blood cells, so the person has to breathe harder, trying to get more oxygen.
D) The lungs do not efficiently take up the deformed red blood cells, so the person has to breathe harder, trying to get more oxygen.
E) Sickle cell disease kills off red blood cells, so the body does not receive sufficient oxygen and the person must breath harder.