Answer: Observation
Explanation:
The scientific method is the way that facts are established. It takes a series of steps to prove a fact. This starts from making an observation, forming a hypothesis, testing it in an experiment and depending on the results, drawing a conclusion which may prove the theory right or wrong.
Sachiko sees a relationship between open umbrellas and small car accidents. this is just an observation and if she wants to declare it as a scientific fact, it needs to undergo all the listed steps mentioned above.
