CTET Class I to V 2016 Feb Paper

A Class V teacher takes an aluminium foil and puts it in water and shows that it floats. She then crumples and squeezes the foil tightly and puts it in water again and shows to the students that it sinks. She then asks the students to think and give reasons why they think this has happened. Which one of the following process skills will be used in answering this question?