Which of the following could be described as a benefit of using a vault?

A vault can indeed be described as providing a benefit by preventing soil movement. This structural integrity is particularly important during the burial process and after interment, as it helps maintain the stability of the grave site. By preventing the collapse of soil above the casket, vaults contribute to the long-term preservation of the grave site, ensuring that it remains properly defined and undisturbed.

Additionally, while other options mention various aspects of vaults, such as ground obstruction and aesthetic value, they do not directly relate to the primary functional benefits that vaults are designed to provide. The option regarding cost is also less relevant, as vaults are typically considered a more protective expense rather than a cheaper alternative in burial practices. The key takeaway is the vault's role in maintaining the integrity and stability of the burial site, which is crucial for both respect for the deceased and the upkeep of the cemetery.