The Most Promising Gene Therapy Strategy for I-Cell Disease Is

The most promising gene therapy strategy for I-cell disease is to:

A) Introduce an intact copy of the a-L-iduronidase gene.
B) Replace a normal copy of the iduronate sulfatase gene with one containing a nuclear localization signal.
C) Replace the N-acetyl-galactosamine transferase gene with one containing a lysosomal localization signal.
D) Replace a faulty copy of the mannose-6-phosphate transferase gene with a functional copy.
E) Replace all lysosomal enzyme genes.