What do both parties have a continuing duty to supplement their disclosures of?

The correct answer pertains to both parties having an enduring obligation to update the disclosures of witnesses and documents relevant to a case. In legal proceedings, particularly during the discovery phase, it is crucial for parties to disclose all potential evidence that may be presented at trial. This includes notifying each other of any witnesses who may testify, as their availability and relevance could change over time. Additionally, parties must share any documents that are pertinent to the case that may come to light after initial disclosures.

The ongoing duty to supplement disclosures ensures that both parties have access to the same information and can adequately prepare their cases without one side withholding crucial evidence. It promotes fairness and transparency in legal proceedings, allowing for a fair opportunity to argue their respective positions.

In contrast, other choices focus on aspects that do not typically carry the same obligation to supplement disclosures. For example, evidence and exhibits can be presented at trial without the same requirement for continual disclosure updates once they are shared initially. Similarly, arguments and testimonies may evolve, but parties are not legally required to continuously disclose changes. Prehearing notes and deadlines do not fit into the category of disclosures governed by these rules, as they pertain more to procedural management rather than substantive evidence related to the case.