The electoral college is the system that is used in the United States in presidential elections. It is a body of electors chosen by the voters in each state to elect the president and vice president of the U.S.
The federal government is composed of three distinct branches: legislative, executive, and judicial. The president presides over the executive branch of the federal government. So a textbook on the U.S. government will definitely provide more information on the presidential election process than the sources mentioned in A, B, D.
