Answer:
A. inheriting a specific gene
Step-by-step explanation:
because sickle cell anemia is caused by a mutation in the gene responsible for making hemoglobin that makes blood red and enable the rbcs to carry o2 from lungs to the whole body.
but both mother and father must pass the defective gene to the child to be sick with sickle cell anemia otherwise the child will carry the gene but shows no sign of the anemia.