Tbh I don't understand what u are asking
I think it should be main idea.
The correct answer should be additionally.
The word additionally would provide the best transition between these two sentence. It is so because you have one idea in the first sentence, and then you want to show another idea very similar to the first one in the second sentence. Using additionally to convey that is the way to go.
The right answer for the question that is being asked and shown above is that: the <span>two questions did Harriet ask in her mind when she witnessed the suffering of her people is that </span>"Why should the farm animals live better than my people?" and <span>"Aren't there laws against this harsh treatment?" </span>
So the old buccaneer could be independent