The correct answer is A. Porter is writing social history because he is focusing on the lives of large numbers of ordinary people.
Explanation:
History refers to the field that studies the events of the past and focusing on creating official documents that describe them; additionally, in history there are different types of history or approaches that focus on different aspects of the past in the case of social history this is the type of history that does not only at studying the way events occurred but on the social effect it has including the perspectives of people about events and life of people. This therefore, is the type of history Porter is writing because he is trying to understand through multiple sources the perspective of people about the influenza pandemic mainly by studying the fear people had and the effect this has on people, which shows he focuses on lives of multiple ordinary people instead of focusing on the economic, medical aspects or other that are not related to the social aspects.
