The correct answer is B) they were developing a separate identity.
The option that best describes the change occurring in American colonies as the 1700s progressed was that they were developing a separate identity.
Although most of the colonist of the Americas came from England, they had different backgrounds and interests. Some left Britain because were persecuted for political reasons. Others had differences with the Church of England and had to emigrate. Many others wanted to start a new life and America was the best option.
These idiosyncrasies did not affect the settlements in the first years but they started to be part of the differences between many of the colonies as time passed by. The differences between the Puritans, the Quakers, the Pilgrims, the people from Virginia or Pennsylvania marked the essence of each colony.