Normally you can't. You cannot tell if water has been frozen and then thawed.
Answer:
When you move into a new home or apartment, the first thing on your checklist should be to have the <u>locks</u> changed
Explanation:
Changing the locks
Given that the way the previous owners of the new home or apartment made use of the locks and the keys are usually not completely known to the new owners, one may never know all those that have a key or a means to gain access into the apartment or home. Therefore, in order to guarantee proper security, it is a good practice to have as one of the first thing on the checklist, the changing of the locks of the entrance doors and windows of the new home or apartment.
I personally feel that e-mail can be used for more business settings and as a more formal approach to things as opposed to a text, but option C seems to be more of an opinion. I would go with C or D.
Some proteins must be altered before they become functional.