Answer:
a) By repeating trials during an experiment
Step-by-step explanation:
In science, repetition during experimentation is extremely important and fundamental. By repeting experiments, the researcher ensures that results are reliable and not due to a single factor or coincidence. If the same result is observed after several repetitions, then it could indicate that x factor is responsible for x result.
After this observation, the researcher will be able to analyze data statistically and discuss it in order for other scientists to repeat this methodology and explain a specific phenomenon accurately and thoroughly.