What provision excludes coverage for a lost item of considerable value if the cause cannot be sufficiently explained?

The provision that excludes coverage for a lost item of considerable value when the cause cannot be sufficiently explained is known as "mysterious disappearance." This term specifically addresses situations where an item has gone missing without any clear explanation or evidence of how it was lost, which creates challenges in determining liability or the specifics of the incident.

Mysterious disappearance is a common exclusion in insurance policies, especially for personal property coverage. Insurers require proof of loss or a clear understanding of how the loss occurred to be able to provide compensation. When an item is reported as lost without any details explaining its disappearance, it may lead insurers to deny the claim based on the absence of evidence needed to substantiate the loss.

In contrast, the other options refer to different concepts. A negligence clause typically pertains to loss resulting from the insured’s failure to take reasonable care of the property. An exclusion clause usually outlines specific circumstances or perils that are not covered under a policy. A non-disclosure clause addresses the requirement to disclose significant information during the insurance application process, not about the circumstances of loss. Therefore, mysterious disappearance directly relates to the unexplainable loss of an item of considerable value.