Final answer:
Frank's casket is named after its owner, Frank. The practice of personalizing possessions with names or identifiers was common in the past.
Step-by-step explanation:
Frank's casket is called so because it belonged to an individual named Frank. The name 'Frank' is likely a personal or familial name associated with the owner of the casket. This type of personalization was common in the past, where people would personalize their possessions using their names or other identifiers.