Answer:
The answer would be A. People from many different backgrounds.
Explanation:
A quote that would support this is: "They attracted people from many different European backgrounds: Dutch, Scot-Irish, Scandinavian, German and French."
B is incorrect because the quote from letter A proves it wrong.
C is incorrect because it isn't the focus of the text.
D is incorrect because according to the quote, "Colonists practiced many different religions," it is clear that there was also a variety of religions in the Middle Colonies (<em>not</em><em> </em><em>just</em><em> </em><em>one</em><em> </em><em>religion</em>).