When Political Parties Are Working Properly, They Do a Number

When political parties are working properly, they do a number of things that make popular sovereignty possible. For example, political parties

A) provide a mechanism for keeping elected officials responsive and responsible.
B) allow voters to directly elect the president.
C) insist that all elections should be nonpartisan in nature.
D) increase their impact by funneling more campaign contributions to candidates.
E) all of the above