The correct answer is D. 1, 2 and 3.
Observation and measurement are the first steps in the scientific method. Scientists observe the natural world and make measurements to gather data. This data is then used to formulate a hypothesis, which is a tentative explanation for a phenomenon. The hypothesis is then tested through experimentation. Experiments are designed to control variables and isolate the effects of one variable on another. The results of experiments are then analyzed and tabulated. This data is used to draw conclusions about the hypothesis. The conclusions are then used to form a theory, which is a well-substantiated explanation for a wide range of observations. Theories can be used to make predictions about the natural world. These predictions can then be tested through further experimentation.
Representation is not a method of science. It is a way of communicating the results of scientific research. Scientific results can be represented in a variety of ways, including graphs, charts, tables, and models.