People living in lands conquered by islamic leaders were not forced to convert to islam , but one reason that many converted anyways was that

b. native americans them

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.