Answer: D.
Explanation: It means the House is about to take a formal vote. To do this, MPs pass out of the Chamber into one of two lobbies, depending on whether they vote 'aye' or 'no' to the proposal. The lobbies must first be cleared of any non-MPs or MPs who don't wish to vote, to ensure only MPs who are voting for either 'aye' or 'no' are present in the lobbies at the time of the division.