From 1901 to 2013, 30.7 percent of us foreign born citizens recieved nobel prizes

From 1901 to 2013, 30.7 percent of us foreign born citizens recieved Nobel prizes reflecting that immigrants make important contributions to the United States.

Immigrations, and the ease and openess of U.S academia to sholars from across the world is one of the  most significant and remarkable reasons that make American higher education truly exceptional.

answer: b.

explanation:

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."