CRISPR May Work to Treat Sickle-Cell Disease by Targeting

CRISPR may work to treat sickle-cell disease by targeting

A) faulty portions of the hemoglobin gene within the genome of cells and removing and replacing those portions with normal sequences of nucleotides.
B) and attacking faulty hemoglobin molecules within red blood cells, so that new normal molecules may take their places.
C) and attacking red blood cells that carry faulty hemoglobin molecules, so that new normal red blood cells may take their place.
D) the mRNA produced during the expression of the hemoglobin protein, removing and replacing faulty portions with correct sequences.