B is the correct sentence. The second phrase is related, but can be its own sentence.
America has changed over time in many different ways. For example, America has become more multicultural. Although America always had people of different nations, the trend is even more significant now, as people from almost every nation of the world live in America. We have also become more accepting of this, with laws that outlaw segregation and discrimination.
America's treatment of Native American people has also changed over time. During the early years of the country, Native Americans suffered greatly from loss of land, death, discrimination and poverty. In recent years, the government has tried to solve many of these problems by giving Native Americans citizenship, as well as more autonomy.
However, these problems are far from being solved. America still has a long way to go before Native Americans achieve full equality. Native Americans would benefit from better education. They also need more autonomy over their resources, and for their cultural legacy to be more protected.
I believe the answer is c. appositive phrase
What are those pink things over there? This is our last chance to do the right thing. somebody call 911! I've got to say: I'm feeling pretty proud of myself right now. you have no idea who you're messing with. Just who do you think you are?
