The role of The Protestant Reformation in the history of the United States of America. Over the centuries there had been many reform efforts within the Catholic Church, The term Protestant was not initially applied to the reformers, but later was used to describe all groups protesting Roman Catholic orthodoxy.
I'd say the answer is A because it's saying there is diversity in their culture because some people are muslim and others have different religions and cultures.
J. Robert Oppenheimer is often called the "father of the atomic bomb" for leading the Manhattan Project, the program that developed the first nuclear weapon during World War II.
Washington Gladden's ideas would most closely be tied to the period in U.S. history that begins just after the Civil War and leads into Reconstruction.