The first one, a brother & sister that immigrated to the Us from Ireland as children. The reason why is because they experienced the struggles as an immigrant first hand instead of using someone else's story, giving it more credibility.
I believe the answer is A.
Rene Descartes was a French mathematician wherein he was coined to be the "Father of Modern Philosophy." He was famously credited to the line "I think, therefore I am" in which he was the leading figure in the development of mechanistic sciences. In addition, the excerpt most likely conveys the Descartes used a modest tone.
