The Americans were huge areas of fertile land, and the European powers needed people to work on its fields. African slaves were a cheap and abundant solution.
Even though the map wasn't provided, it is possible to answer the question by saying that the correct alternative is letter<em> A: Nazi leaders wanted to keep the existence of extermination camps secret.</em>
The extermination camps were built to murder sistematically jewish, communist and all other kinds of people that the Nazi considered inferior. The idea was to have them in hidden places so as not to cause commotion.
I think it's D. Hindu- Arabic Numerals
