Answer:
A
Explanation:
The scientist first has to test the drug on a trail run as it cannot be directly brought into the market for selling as the drug may contain some side effects and may not work properly as the scientist intended .The scientist may have commited some mistake in the preparation of the drug that is some sort of excess or reduced usage of one of its components may not lead to the fruitful results so the scientist has to test the composite drug in a trail run.
