Which of the following is not a subsidiary motion?

A main motion is a proposal that brings new business before the assembly, and it serves as the primary means for members to introduce topics for discussion and decision-making within a meeting. Unlike subsidiary motions, which are used to modify or manage the primary motion introduced, a main motion is not derived from or contingent upon another motion. The other options represent common subsidiary motions that serve specific purposes: "Postpone Indefinitely" allows members to dismiss the main motion without a direct vote, "Commit or Refer" enables the assembly to send the matter to a committee for further review, and "Amend" permits modifications to the main motion. These motions are all aimed at managing the process of the main motion and directly influence how it is handled in the meeting, which distinguishes them from the main motion itself.