Stem cells can become any type of cell in the human body, making them ideal for many types of therapies. One area of possible use is in brain cell transplants that could help people with spinal cord injuries and neurodegenerative diseases such as Parkinson’s disease. Even though there is great potential for helping people, what is one ethical issue that could arise from the use of stem cells?

A. the source of the stem cells
B. the cost of obtaining the stem cells
C. the method of storing the stem cells
D. the procedure for transplanting the stem cells