To accurately determine the author's opinion on how the Spanish treated the Native Americans, we would need to analyze the text or passages related to the author's views. Based on the options provided, if the text conveys criticism of the Spanish treatment of Native Americans, the most fitting response would be:
The author feels strongly that the Spanish explorers were NOT justified in their treatment of the Native Americans.
However, if the text does not express any strong opinions and only presents factual information, then the appropriate response would be:
The author does not seem to have an opinion, only stating facts.
Please refer to the specific text or context to choose the most accurate response.