The correct answer is C. Sworn statement from the courier that the set was delivered in its entirety . The key issue is proving when and where the loss occurred. If several antique encyclopedias are missing after an after-hours delivery, the insurer must determine whether the property was actually delivered complete to the bookstore or whether the loss occurred before delivery while in the courier's responsibility. A commercial property broad form may cover insured property at the described premises if the loss is caused by an insured peril and the insured can establish that the property was present and complete before the loss. A sworn statement from the courier confirming the full set was delivered would support the argument that the missing items disappeared after delivery, while the goods were at the insured premises. A mysterious disappearance explanation alone is weak and may be excluded or difficult to prove. A fidelity declaration would be inappropriate unless employee dishonesty is involved. Care, custody, and control wording is more commonly associated with liability exclusions and property of others, not the specific proof needed here. Course topic reference: Property Coverages; Commercial Property Broad Form; Proof of Loss; Property at Insured Premises; Theft and Disappearance Issues .