Answer:
b. the first action by itself raises U.S. net exports, the second action by itself lowers U.S. net capital outflow.
Step-by-step explanation:
Net exports are equal to the difference between the value of a nation's total export of goods, services and the value of all the goods and services it imports.
U.S. net export raises as more British decide to vacation in the U.S. and U.S. net capital outflow reduces as the British purchase more U.S. Treasury bonds.
So, option b is correct.