How was portugal able to conquer the kingdom of congo? a. portugal had conquered all the surrounding territories. b. portugal had allies who lived within the territory. c. the trade of slaves weakened the rulers. d. the portuguese military was much larger.

C. The trade of slaves weakened the rulers.

Portugal was able to conquer the kingdom of Congo as the monarchy had an agreement to concede part of the population as slaves, which in years weakened the primary power present at the time, allowing the Europe nation to take advantage of this fact and conquer the country for itself, thanks to the weak primary power present.