The following passage is from an address by President Barack Obama: My fellow Americans, we are and always will be a nation of immigrants. We were strangers once , too. And whether our forebears were strangers who crossed the Atlantic, or the Pacific or the Rio Grande, we are here only here because this country welcomed them in , and taught them that to be an American is about something more than what we look like , or what our last names are, or how we worship. What makes us Americans is our shared commitment to an ideal-that all of us are created equal , and all of us have the chance to make our lives what we will.

- Barack Obama, November 20,2014

What is the main point of this passage?
A - Cultural diversity makes the country strong.
B - Immigrants to the United States should learn English
C - Certain shared values help unite all Americans.
D - All Americans should believe the same things.