PLEASE HELP 10 POINTS + BRAINLIEST!!!!!

Which of the following is an example of an experimental procedure that can help you get accurate results in an experiment?
I wonder if magnets attract all metal objects?
I notice that the magnet attracted the paper clip and the nail but not the gold ring or the copper penny.
I observe that magnets attract metal things.
I must test all objects in the same way to get accurate results.