Final answer:
The correct option is A). An experiment is a research method that tests hypotheses to establish causality, involving observation, hypothesis formulation, testing, and confirmation or falsification of the hypothesis.
Step-by-step explanation:
A research method that tests hypotheses and allows researchers to make conclusions about causality is called a(n) experiment. An experiment is a scientific approach where researchers investigate relationships to test hypotheses. In this context, conducting an experiment involves defined steps that include observation, formulation of a hypothesis, testing, and confirming or falsifying the hypothesis.
During the scientific method, a hypothesis is a proposed explanation for a phenomenon that can be tested through experimentation. If the data analysis from experiments supports the hypothesis, it may lead to further testing and refinement. If the hypothesis is rejected, a new hypothesis may be formulated. Over time, repeatedly supported hypotheses can contribute to scientific theory, which is a thoroughly tested and confirmed explanation for observations or phenomena.