Answer:
The date marking the end of prehistory is typically defined as the contemporary Written historical record for example in Egypt it is generally accepted that pre history ended around 3200 BCE
If Gina remarks: "it feels cold in here" and her two friends agree with her this shared sense of an objective experience is an example of the suggestion.
When Gina said "it feels cold in here" she influenced her two friends to realize the same thing and confirm it.
