The Use of Cell-Based Models to Understand or Treat Human

The use of cell-based models to understand or treat human disease processes is aided by stem cells in all the following ways,except:

A) growth of neurons in cell culture containing mutations associated with ALS for drug screening.
B) culture of patient-specific cells to replace those lost to disease,such as for type 2 diabetes.
C) differentiation of neurons from iPS cells to replace those damaged by neurodegenerative diseases.
D) provides proof that ES cells are pluripotent and can divide to make a normal animal.