Answer:
B. It sent missionaries to convert American Indians
Step-by-step explanation:
D. is effectively the way they did established their empire in the Americas. They tried missionaries as another strategy to establish its empire in the Americas:
"Throughout the colonial period, the missions Spain established would serve several objectives. The first would be to convert natives to Christianity. The second would be to pacify the areas for colonial purposes. A third objective was to acculturate the natives to Spanish cultural norms so that they could move from mission status to parish status as full members of the congregation."
Reference: Nps.gov. (2019). The Significance of Spanish Colonial Missions in our National Story and our Common Heritage with Spain, Mexico and Latin America (U.S. National Park Service). [online]