The correct answer to this open question is the following,
If the President of the United States wishes to consult with a member of his staff regarding the possibility of expanding trade with Indonesia, he should consult a member of the Executive Office of the President.
This is the Office of United States Trade Representative because the officer advises the President of the United States about foreign trade expansion, new agreements or difficulties with previous agreements with other countries. So If the President of the United States wishes to consult with a member of his staff regarding the possibility of expanding trade with Indonesia, he should consult the Office of United States Trade Representative.