The Availability of ADRs That Can Be Bought and Sold

The availability of ADRs that can be bought and sold on U.S. stock markets most likely:

A) increases the total amount of direct purchases of foreign stocks by Americans.
B) decreases the total amount of direct purchases of foreign stocks by Americans.
C) has no effect whatsoever on the total amount of foreign investment by Americans.
D) increases the amount of U.S. assets acquired by foreign investors.