Hello! needing assistants :p would be well appreciated like alot. *brainlest included *

Finn listed two of the three steps involved in gene therapy. 1. The normal allele is removed from the chromosome. 2. The normal allele is added to the cells of a person with the disorder.

Which step should he also include, and where?

a) The normal allele is copied before step 1.
b) The normal allele is copied after step 1.
c) The unhealthy gene is cut from the DNA before step 2.
d) The unhealthy gene is cut from the DNA after step 2.d