This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Sickle cell disease is: 
Select and explain. 
A. Inherited as AR, B. Inherited as AD, C. Inherited as XLR, D. Inherited as XLD
A: Inherited as AR
Answer: A: Inherited as AR 
Explanation: Inherited as AR