Which type of amendment allows for more than one change to a motion?

The option indicating "Second Order" is correct because it refers to amendments that allow for multiple changes to be proposed for a primary motion. In parliamentary procedure, a second-order amendment is one that is made to an already amended motion, enabling more than one layer of amendments to be discussed and potentially adopted. This flexibility is crucial in a debate because it allows members of an assembly to refine and adjust proposals to better reflect the group's intentions and needs.

In contrast, first-order amendments typically only address the original motion without permitting additional changes. Unanimous consent is a process used to expedite decisions without formal voting when no one opposes, and a closed amendment is a type of amendment that restricts debate or amendments to a motion, allowing only the specific changes proposed.