Please i need the answer im dying here ;- What happens when matter changes state? (choose one from the following :))

Its chemical properties change.
Its physical properties change.
The energy of its particles remains the same.
none of the above

anawer is none of the above

Control group:

Test section covered with the "Steel Seal" floor wax

Explanation:

In a scientific experiment, the control group is the standard group to which comparison is made, to determine the effect of the experimental agent on the test subjects. In this example, the Steal Seal floor wax is the standard wax being used, and the experimenter wants to see if the "Tough Stuff" wax is better, hence after the treatment with the Tough Stuff wax, the number of scratches observed is compared with the standard wax area and the difference determines if it is a better waxing agent or not.