Final answer:
The two brothers in Ellis's story differ in that one has found a successful career and fulfillment, while the other is still seeking his own path in life.
Step-by-step explanation:
Part A of the question asks about the differences between two brothers in Ellis's story. The statement that best explains how they differ from one another is A. One brother has found a career in which he is successful and fulfilled, while the other is still in search of his own fulfillment. This notion is supported by the given narrative excerpts, suggesting one brother as being settled in his career and life, and the other still navigating his path. The narrative also alludes to the first brother being mild and patient, possibly indicative of his contentment with life, whereas the second brother's circumstances or temperament might be such that he is still exploring or struggling with his place in the world.