U still have school its summer
I have no clue, there is nothing else here to support your question.
"D: A new gene, which codes for the protein that can repair defective genes, is introduced."
Explanation: <span>Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery.</span>