The correct answer is A. Ashlar arch.
An ashlar arch is a type of arch that is made from ashlar masonry, which is a type of masonry that is made from large, finely cut stones. Ashlar arches are often used in high-class buildings where appearance is of prime importance.
A rubble arch is a type of arch that is made from rubble masonry, which is a type of masonry that is made from small, irregularly shaped stones. Rubble arches are often used in less expensive buildings where appearance is not of prime importance.
A gauged brick arch is a type of arch that is made from gauged bricks, which are bricks that are cut to a precise size. Gauged brick arches are often used in buildings where a high degree of precision is required.
An axed brick arch is a type of arch that is made from axed bricks, which are bricks that are cut with an axe. Axed brick arches are often used in buildings where a rustic appearance is desired.