I believe the answer is: Explain
Explain is the act of figuring out how things turn out as it is. In scientific field, to obtain proper explanations, researchers need to construct a hypothesis and tested them with proper scientific method in order to find relevant facts that might connected to the occurrence.
Flint was used to make some tools and weapons.
Medical results are valid for twelve months from the date of the exam. The answer is A.
Answer:
C seems the strongest and best.
Explanation: