A deliberative assembly that has not adopted rules is governed by which of the following?

In a deliberative assembly that has not adopted specific rules, the assembly defaults to the rules of common parliamentary law. These rules are designed to ensure fair and orderly conduct of meetings, and they provide a framework for making decisions, debating issues, and conducting votes. Common parliamentary law is typically based on established practices and precedents that have evolved over time to maintain order and justice in meetings.

This option is correct because common parliamentary law is recognized as the underlying structure that guides the proceedings in the absence of customized guidance from either adopted rules or bylaws. It serves as a reliable reference for resolving procedural matters and ensures that all members have a clear understanding of the protocols in place, promoting effectiveness and fairness in the assembly's operations.

The other options suggest authorities that do not provide the same level of established procedural guidance. The decisions of past assemblies may offer insights but do not constitute an actionable framework for current proceedings. Similarly, the opinions of the chairperson alone cannot dictate assembly conduct, as this risks introducing bias and undermining democratic processes. Lastly, reliance on the majority opinion of all members lacks specific structure needed for procedural fairness, as it could lead to arbitrary interpretations without a solid basis in conventional rules.