Answer:
a. the principle of comity.
Step-by-step explanation:
Since in the question it is given that Retail Operations, Inc which is a U.S firm received the judgement in a court that is U.S based in opposite to the Shinobu, Ltd i..e Japanese business
So as per the given situation, here it applied the comity principle as it is a legal reciprocity in which one jurisdiction would extend specific courtesies for the other nations
hence, the option a is correct