You really put a whole test without answering anything-
Answer:
A. that the United States was powerful enough to stop new colonization in the Americas
Explanation:
The Monroe Doctrine basically stated that the US would stay out of European affairs while warning Europe not to interfere in the Americas or else
It is a true fact that Caliphs recruited Persians and Turks as government officials. The correct answer among the two options that are given in the question is the first option or option "a". Caliphs were the most powerful people of that time. I hope the answer comes to your help.