Forty-five million people in the U.S. — about one in six adults — owe a total of $1.7 trillion in student-loan debt. Canceling some of these federal loans has become a flash point in modern American politics. In a new book, Burdened: Student Debt and the Making of an American Crisis, Ryann Liebenthal traces the origins of the student-loan system and breaks down how it works today. Liebenthal spoke with Apple News In Conversation host Shumita Basu about ways to address this trillion-dollar problem.