In the United States, it would be the telephone industry that is often considered part of an oligopoly (among other things), since only a small handful of companies dominates the market.
The answer is b because it basically explains it oby
Jacob Riis's book How The Other Half Lives, written in 1890, remains an outstanding example of the importance of investigative journalism and the continued vitality of the Fourth Estate. Jacob Riis was among the earliest of what Theodore Roosevelt later termed " muckraker", "taking the rake to uncover the most unpleasant conditions in American society."
