What is the length of a standard adult metal casket expressed as a fraction?

The correct answer is based on standard measurements for adult metal caskets, which typically measure around 6 feet (or 72 inches) in length. To express this measurement as a fraction, we can represent the total length of a casket as 6 feet over a reference length of 6 feet. This gives us the fraction 6/6, which simplifies to 1.

In this context, the fraction accurately represents the full measurement of an adult casket in comparison to itself, making it a valid and correct way to express the length. Other options do not appropriately represent the measurement of a casket in this context. For example, while 5/6 represents a value less than the full length, the other fractions presented do not align with standard casket dimensions or do not provide a meaningful context for expressing the length of a casket.