to obtain data to test a hypothesis to make a complete observation to make a report of the procedures to make a hypothesis understandable
I gave my students this multiple choice question: During a space mission, scientists will send experiments for the astronauts to conduct in space. In many cases, scientists have made predictions about the outcome of the experiment. Why do astronauts perform the experiment if the results have already been predicted?

Only one answer is correct among these 4 choices:
- to obtain data to test a hypothesis
- to make a complete observation
- to make a report of the procedures
- to make a hypothesis understandable

Could you tell me which one is correct?

to obtain data to test a hypothesis