Answer:
a. Repeat the experiment using a stopwatch that functions correctly.
Explanation:
Options B and C represent something very wrong. In a scientific research, we should never manipulate the data of the evaluations, besides being illegal it loses all the credibility of the research and the researched one. Scientific research cannot be based on measurements made with broken devices either, because the result of such research would not be right and research should always be committed to the dissemination of true data. The letter D is not correct either, when something from a wrong search we must think about how to use other means to replace what went wrong and not abandon the search.
For these reasons, we can conclude that the right option for your question is the letter A. The correct option would be to replace the broken device and redo data collection.
