Answer:
According to the context in which General MacArthur lived, and according to the possible meanings from the dictionary, the best definition for General MacArthur's use of the word dictate is the third one: an order that must be obeyed.
Step-by-step explanation:
To respond to this question, we have to be sure to know who General Douglas MacArthur was, and what he did for a living: MacArthur was a military man from America; he was the most decorated military in the history of the United States of America. He also was a five-star general of the United States Army and field marshal of the Philippine Army. He acted as supreme allied commander in the Pacific Front during World War II. After we are aware of who he was and what he did, we can decide which of the meanings from the dictionary is the right one in this case. Here, the best definition is "an order that must be obeyed" because he lived in that context: one of giving and receiving orders. A reality where is common to give orders to people and receiving orders from superiors. The third one is the definition that best fits.