The president has traveled out of the country in order to strengthen the trading bonds with japan. this is known as: vacation judicial review diplomatic relations statutory construction

It is definitely not vacation: vacation would imply that the president is not at work, and the description above describes his work.
It's also not a judicial review, as it's something that the Supreme Court does, not the president.

The correct answer is: diplomatic relations! those refer to improving the relationships between the countries.