Which motion allows members to delay consideration of a main motion?

The motion that allows members to delay consideration of a main motion is indeed "Postpone Indefinitely." This motion serves the purpose of effectively setting aside a main motion and preventing further discussion or action on it during the current meeting. By adopting this motion, the assembly can choose not to consider the main motion at all, allowing time for members to gather more information or for circumstances to change before revisiting the issue.

In contrast, other options do not serve the same purpose. For example, "Amend" is used to modify the wording of a motion or resolution, while "Refer to a Committee" involves sending the main motion to a committee for further review and discussion, but does not delay consideration within the current assembly meeting. "Lay on the Table" temporarily pauses consideration of a motion, but it is meant to allow the assembly to deal with more urgent matters rather than providing a long-term delay of the main motion.

Thus, "Postpone Indefinitely" is clearly the correct answer as it specifically provides a means to delay and potentially prevent any action on a main motion.