Which of the Following Requirements Must Be Fulfilled Before a Gene

Which of the following requirements must be fulfilled before a gene therapy procedure will be approved?
1) The gene must be cloned and well characterized
2) The risks of gene therapy to the patient must have been carefully evaluated and shown to be minimum
3) The disease must not be treatable by other strategies

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these