I think was committees of correspondence.
Answer:
D is the correct answer
Explanation:That new regular army developed the techniques of battle and siege that were used to achieve most of the 14th-century Ottoman conquests, but, because it was commanded by members of the Turkish notable class, it became the major vehicle for their rise to predominance over the sultans, whose direct military supporters ...:0
C. Opportunity cost
This is the opportuntiy that they lost. it costed them. Thus, opportunity cost for another opportunity.
Europeans that migrated to the Americas came here in search of wealth. They ended up almost putting the Native American into extinction. They also enslaved them, tricked them, and forced them to live on reservations. They celebrated this with a holiday we now call Thanksgiving.
The Africans did not choose to migrate to the Americas. They were brought here on slave ships with disgusting conditions. Many of them died along the way. Africans were forced into slavery for hundreds of years. When slavery was abolished Blacks still endured hardships for many many years, even until now.
For the most part, Europeans, Africans, and Native Americans have pretty civilized relations today.