What characterizes insufficient complaints?

Insufficient complaints are characterized by a lack of adequate evidence or basis for taking action. In legal contexts, complaints must present sufficient facts to support a claim or allegation against a party. When a complaint is deemed insufficient, it typically lacks the necessary detail, supporting facts, or legal grounding that would allow a court or relevant authority to proceed with the case. This means that the complaint does not provide enough information to justify legal intervention or investigation, leading to its classification as insufficient.

In contrast, the other answer choices do not accurately capture this meaning. Clear evidence for action suggests that the complaint is well-founded and merits attention, which contradicts the idea of insufficiency. Similarly, having enough basis for action denotes a solid framework for a complaint that could potentially lead to actionable outcomes. Lastly, saying that they must always be investigated implies a requirement that is not applicable to insufficient complaints, as they may not even warrant investigation if they lack substantive evidence. Thus, the correct characterization of insufficient complaints centers on their failure to provide adequate support for a potential legal action.