The immune disorder adenosine deaminase (ADA)deficiency is the result of a mutation in one gene. How could gene therapy be used to treat this disorder?

A)Red blood cells could be induced to produce the protein encoded by the mutated ADA gene.
B)Cells containing a corrected ADA gene could be injected into patients with ADA.
C)The patients could swallow synthetic blood cells.
D)Patients could be injected with a hybrid molecule made of the DNA and RNA of the normal ADA gene.