The correct answer is the third one: It led to the collection of several complete data sets.
In this particular scenario, the scientist is following the experimental scientific method. This method is based on observations, a hypothesis that explains the observations, and experimentation in order to collect data to check the hypothesis. This method is fueled by skepticism, meaning that the scientist is not blindly believing the information given by the first collection of data, whether it confirms or rejects the hypothesis. On the contrary, she still repeats the experiment several times in order to collect different sets of data. She does so because she knows that by comparing different sets of data she would get a better picture of the entire experiment so, the more data she gets the more accurate the conclusions will be.