Concept:A registered parcel notice is delivered through a postal slip when the addressee is not available to receive it directly.
Explanation:Registered parcels require a signature upon delivery.
If the postman cannot find the addressee at home, the parcel is not left unattended.
Instead, the post office leaves a small paper notice at the addressee’s address.
This notice contains information about the parcel and the post office where it is kept.
The addressee must take this slip to the post office to claim the registered parcel.
Therefore, among the given options, the item used to inform the addressee is the slip.
A counterfoil is kept as a record, an express label indicates speed, and a telegram is a message.
Hence, the correct choice is the slip.
Answer:C. Slip