What Was the Purpose of the 1907 "Gentlemen's Agreement" Between

What was the purpose of the 1907 "Gentlemen's Agreement" between the United States and Japan?

A) To allow greater Japanese immigration into the United States
B) To forge an alliance between the United States and Japan in case war broke out with China
C) To allow the Japanese to save face by voluntarily restricting immigration to the United States
D) To condemn Russia for supporting Chinese goals