Final answer:
The most powerful member of the House of Representatives is the Speaker of the House. This individual is elected by the entire body and serves as the presiding officer, the administrative head, and the leader of the majority party, as well as being second in line for presidential succession.
Step-by-step explanation:
The most powerful member of the House of Representatives is (a) Speaker of the House. The Speaker is elected by the entire body of representatives and holds several roles: the presiding officer of the House, the administrative head, the leader of the majority party, and the representative of a single congressional district. Notably, the Speaker is also second in line to succeed the president, demonstrating the position's significance.
Members of both the majority and minority parties elect their respective leaders, with the party holding the majority electing the Speaker. The hierarchy of power under the Speaker includes the majority and minority leaders followed by the whips. Although committee chairs have significant influence within their committees, they do not surpass the Speaker in terms of overall power in the House.