There are several categories in which we can classify conflict. In this case, the conflict is an instance of "man vs. society." "Man" refers to the protagonist of the story (in this case, the father). On the other hand, society refers to any social construct, such as the government, society at large or a particular organization, such as a school or a club.
Compound there are two sentences connected by a semicolon, you can tell because they each have their own subject (the musician, she) and their own verb (preform, had).
The answer b states that "from then on" meaning her behavior has changed toward her brother and the passage states how she has been putting a little extra thought into how she interacts with her brother.
