The correct answer is option A. Porter is writing social history because he is focusing on lives of large numbers of ordinary people. He is examining letters, journal entries, autobiographies and newspapers from that time to see how the fear of the disease affected the lives of ordinary people. Porter is trying to recollect data from that time and put together a piece that describes how society was affected by the influenza pandemic, which was a consequence of World War I, an historic event that shaped and changed many societies, specially the ones from Europe.
