in the recent past which one of the following would be the MOST effective security for a U.S. investor seeking the benefits of global diversification...

in the recent past which one of the following would be the MOSTeffective security for a U.S. investor seeking the benefits of global diversification to add to his/her profile?

a A Canadian corporation's common stock

b. British government bonds

c An Indian corporation's common stock

d.  A Japanese corporation's common stock