The _____ prohibited commercial banks from being in the insurance and investment banking business.

A) Celler-Kefauver Act
B) Sarbanes-Oxley Act
C) Gramm-Leach-Bliley Act
D) Glass-Steagall Act
E) Dodd-Frank Act

The Glass-Steagall Act, passed in 1933, specifically prohibited commercial banks from engaging in the investment banking and insurance businesses, creating a separation between these types of financial activities to reduce conflicts of interest and prevent the kind of bank failures that occurred during the Great Depression.