Which of the following methods is used in empirical research?

Empirical research is research that draws its conclusions from observable, measurable evidence rather than from theory or belief alone. Its central requirement is that claims be supported by data gathered through the senses — by observation, measurement, and experimentation.

The method that embodies this evidence-based, systematic process is the scientific method: it proceeds by observing a phenomenon, framing a hypothesis, designing and running tests, collecting and analysing data, and verifying the results. Because every step is anchored in empirical evidence, the scientific method is the method used in empirical research.

The inductive and deductive methods are modes of reasoning that operate within research, and the intuitive method relies on insight rather than data — so none of them, taken alone, names the overall empirical procedure. Hence the correct answer is the scientific method.