It is answer A because the speaker cannot understand what he did wrong.
Answer:
Explanation:
I want to tell you something, this did not happen in the book outsiders I read i like a thousand times.
Medical research, also known as experimental medicine, encompasses a wide array of research, extending from "basic research", – involving fundamental scientific principles that may apply to a preclinical understanding – to clinical research, which involves studies of people who may be subjects in clinical trials.