The correct answer to this open question is the following.
Although no options are attached, we could say that the best primary source material about the works of Mohandas Gandhi should be their own writings. That is the characteristic of a primary source, the information was written by the character itself of people that directly witnessed the life or events. For instance, there is a book authored by Ronald Duncan, that collects a series of documents written by Gandhi. The name of the book is "Selected Writings of Mahatma Gandhi."
Nine justices serve on the U.S. Supreme Court
Lack of workers was not a problem that cities faced during the Gilded Age.
Western democracies had always been hostile to the idea of a communist state. The United States had refused recognition to the USSR for 16 years after the Bolshevik takeover. I hope my answer has come to your help. God bless and have a nice day ahead!