A.
The narrator says that he had a lot of choices that were difficult to make, but he finally made the decision to leave the orphanage even though it was a tough choice. When he says that "<span>After all, my hate for my father was not so great and urgent as my hate for the orphan home" he shows that he hates living in the orphanage so much that he is willing to face his father just to get out. </span>
The best answer here is chronologically. If we read the excerpt, we can see that the author is starting at the beginning and following a timeline to describe each thing about Gertrude Belle Elion. The other options don't make much sense because there are no interviews cited, though there was obviously come research done. Cause and effect doesn't make sense because there isn't any sort of indication of the causes and effects of certain things except at the end when we find out she never earned her doctorate. The same holds true for problem-solution.
