I'm not positive but I think its the House of Representatives.
The Speaker of the House is elected by popular vote from the other members of the House of Representatives. The Senate chooses a leader by popular vote, but only the majority party can vote.
the president
The Speaker of the House is elected by a majority vote from his/her fellow members of the House.
The Speaker of the House is elected by the members of the House of Representatives. Before the vote each party chooses their candidate. The majority party's candidate will then win the election (assuming his or her party's representatives vote according to the party's decision).
caucus
caucus
The house chooses the speaker of the house
The Speaker of the House of Commons.
the majority party the majority party
The Speaker of the House
Speaker of the Parliament House.
The Speaker of the House is in charge of the House and is third in line to the presidency. She chooses the agenda for the House.
The party with the majority of members in the House since the members of the house chooses the Speaker by a vote. In theory a Speaker could be chosen from the minority party but it has never happened.