Final answer:
The type of vault with a semicircular cross section, also known as cradle, tunnel, or wagon vault, is the Barrel Vault (C). Option C is correct.
Step-by-step explanation:
The type of vault that has a semicircular cross section and is also known as a cradle vault, tunnel vault, or wagon vault is the Barrel Vault (C). Barrel vaults consist of a series of arches placed side by side, forming a continuous, tunnel-like structure.
This simplistic and ancient form of vault has been used throughout history to create interior spaces that resemble a tunnel or barrel. An evolution of the barrel vault is the groin vault, which occurs when two barrel vaults intersect at right angles. This intersection creates an 'X' shape in the ceiling and directs the thrust toward the four corners, mitigating the lateral thrust and allowing for more complexity in the space below.
The type of vault with a semicircular cross section, also known as a cradle vault, tunnel vault, or wagon vault, is a Barrel Vault. Barrel vaults consist of a line of arches in a row that create the shape of a tunnel.