Explanation:
The correct answer is:

C. is hereditary

Sickle cell disease is a genetic disorder, meaning it is inherited from both parents who carry the sickle cell trait. It affects the shape of red blood cells, causing them to become crescent-shaped (sickle-shaped), which can lead to blockages in blood flow and other complications. The disease does not only affect black people, and while it can cause serious health issues, it does not necessarily kill the patient if managed properly.