Final answer:
The FDA can halt the development or use of gene therapy at different points including the IND application stage, during clinical trials, or after the therapy has been manufactured and marketed. All these points are times at which the FDA has regulatory authority to intervene.
Step-by-step explanation:
The FDA can halt the development or use of gene therapy at various stages, which include upon submission of an Investigational New Drug (IND) application, during clinical trials, and after manufacturing and the marketing of the approved therapy has begun. Therefore, the correct answer is d) all of the answers are correct.
For a drug to be approved, the Food and Drug Administration (FDA) requires a series of large-scale experiments using human subjects, ensuring the drug is not harmful and effectively treats the intended condition. This extensive scrutiny is part of the New Drug Application (NDA) process. Only after a drug has been proven safe and effective can it be distributed as a prescription drug.