Hint: The members of parliament are the only federal officials who are directly elected by the public; the parliament, in turn, elects the Chancellor and oversees the executive branch on both substantive policy and routine administration concerns. Binding legislation, public discussions on government policy, investigations, and direct questioning of the chancellor or cabinet officials can all be used to put a check on executive power in place.
The German federal parliament is known as the Bundestag. It is Germany's sole federal representative body that is chosen directly by the people. It is analogous to the House of Representatives in the United States or the House of Commons in the United Kingdom. The Bundestag was formed as one of Germany's legislative bodies in 1949 by Title of the Federal Republic of Germany's Basic Law, and is thus the historical successor to the older Reichstag.
Members of the Bundestag represent the entire German people, are not subject to orders or instructions, and are exclusively answerable to their constituents. The Bundestag has a legal minimum of 598 members; but, due to the overhang and levelling seat system, the current 20th Bundestag has a total of 736 members, making it the largest Bundestag to date.
Note: Every four years, German residents aged 18 and up elect the Bundestag. Elections are held using a mixed-member proportional representation system, in which first-past-the-post elected seats are combined with a proportional party list to ensure that the makeup of the legislature reflects the national popular vote.