Which of the Following Has Not Changed Much as a Percent

Which of the following has not changed much as a percent of GDP over the last twenty years for the United States?
i. the official settlements account
ii. the capital account
iii. the current account

A) i only
B) ii only
C) iii only
D) ii and iii
E) None of the above answers are correct because all three have had large swings over the last 20 years.