Answer:
C) a hypothesis.
Step-by-step explanation:
Option A is incorrect because a thought or a prediction is not equivalent to an experimental question.
Option B is incorrect because observation has to do with taking notes of happenings in the environment.
Option D is incorrect because the prediction is not a form of experiment.
Option E is not correct because controls are only useful during experiments.
The correct option is C.
Hypothesis is a tentative statement, a guess or a prediction that has not been tested by any experiment.