Developed Countries' Stock Market Returns Have Correlations to the U

Developed countries' stock market returns have correlations to the U.S. market that:

A) are stable over the years.
B) seem to maintain their relative rank order to each other compared to the U.S.
C) are consistently correlated to the U.S. markets at less than 1.00.
D) as a group, have seen their correlation decline over the last 42 years.