What Modification Lead to Increased Success of Enzyme Replacement Therapy

What modification lead to increased success of enzyme replacement therapy for Gaucher disease?

A) Removal of phosphate groups to improve targeting to central nervous system
B) Removal of terminal sugars to increase uptake by macrophages
C) Removal of phosphate groups to increase protein half-life
D) Addition of polyethylene glycol to increase protein half-life
E) Addition of terminal sugars to increase uptake by macrophages