Final answer:
The most important document for filing a mechanic's lien is the Notice of Completion, as it establishes the completion of work and the timeframe to file the lien. Notices of Nonresponsibility and Notice of Cessation of Labor may also be relevant but vary by locality.
Step-by-step explanation:
In the context of a mechanic's lien, the most important document required for filing such a lien is typically B) Notice of Completion. This document is critical because it signifies the official completion of work and can be used to establish the timeframe in which the mechanic's lien must be filed. While other documents like Notice of Nonresponsibility and Notice of Cessation of Labor may also be relevant in certain situations, the Notice of Completion often triggers the start of the deadline for filing a mechanic's lien. Different states have different laws governing mechanic's liens, so it's important to check local statutes for specific requirements and timelines.