Under what condition can a motion be debated?

A motion can be debated when it is classified as debatable, which is reflected in the correct answer. This classification is determined by the rules of parliamentary procedure, which outline which motions invite discussion among members. Generally, most main motions and some subsidiary motions are debatable, allowing members to express their opinions and arguments before a decision is made.

The characteristic of being debatable means that members have the opportunity to discuss the pros and cons, fostering a collaborative decision-making environment. This process is essential for thorough deliberation on important issues, as it enables diverse viewpoints to be heard.

While it may seem that other options could provide occasions for debate, they do not accurately capture the established rules governing parliamentary procedure. For instance, simply allowing debate whenever the chair decides or only when there is no opposition does not align with parliamentary standards that determine the debatable nature of motions. Meanwhile, the requirement of a motion being amended before it can be debated misrepresents the fundamental mechanics of how motions operate in a deliberative assembly.