Final answer:
The main character is not explicitly mentioned in the book 'How the Other Half Lives' by journalist Jacob Riis. However, within the context of the question, it can be understood that Jacob Riis himself is portrayed as a compassionate and determined journalist. Through his investigative journalism, Riis exposes the realities of poverty and elicits a call to action from the public.
Step-by-step explanation:
In the book titled How the Other Half Lives (1890), written by journalist Jacob Riis, the main character is never explicitly mentioned, as the book focuses on exposing critical social problems. However, within the context of the question, if the main character is referring to the author himself, Jacob Riis is portrayed as a compassionate and determined journalist who seeks to shed light on the living conditions of the poor in New York City during the late nineteenth century. Through his investigative journalism, Riis is essentially told that he would be a good journalist, as his work uncovers the realities of poverty and elicits a call to action from the public.