Answer: best
Explanation:
In the context of the sentence, "best" is an appropriate word to complete the sentence: "Rafi is the best man in the office." This implies that Rafi is highly regarded or excels in some way among the people in the office.
Other Possible Answers:
most efficient: "Rafi is the most efficient man in the office."
tallest: "Rafi is the tallest man in the office."
only: "Rafi is the only man in the office."