The best approach for Tyler is a controlled experiment if he wants to directly observe the outcome.
A controlled experiment is designed to minimize the effects of the variables other than the independent variable. A controlled experiment allows reliable results because he can do the experiment specific to the problem and variables involved.
"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>
Taking all of them out of their natural environments would disrupt the ecosystem and food chains, and it would be difficult, if not impossible, to place more than a small portion of Earth's endangered species in these facilities.