Which of the following BEST describes the structure of this text?

The text describes the steps involved in the scientific method, which is a process for conducting experiments. The steps are presented in chronological order, starting with the purpose of the experiment and ending with the drawing of conclusions.
The other options are not as accurate descriptions of the text's structure. The cause/effect structure would be more appropriate if the text were describing how one event caused another event. The compare/contrast structure would be more appropriate if the text were comparing or contrasting two different things. The problem/solution structure would be more appropriate if the text were describing a problem and then proposing a solution to that problem.
Therefore, the best description of the structure of the text is sequence.