b. a tall narrow window with a pointed arch at the top
Explanation:
Gothic architecture was developed from the buildings of the Romanesque style, widespread previously. Romanesque architecture was characterized by rounded vaults supported by semicircular arches. Because of these characteristics, Romanesque constructions required heavy and large structures to stand upright. The thick stone pillars guaranteed this support, but limited the height of the buildings and made it difficult for light to enter due to the need to maintain the walls.
Unlike Romanesque architecture, Gothic-style architects developed the pointed vaults, giving the central and lateral nave of the cathedrals a greater dimension. To support them, arches supporting the vaults were built not in semicircle shape, but rather pointed arches, formed from the junction of two segments of circles. This innovation made it possible to increase the height of the buildings, as the technique allowed for greater size flexibility.
To support these arches, the large supporting columns were no longer needed. It was possible to achieve the support with thinner columns, formed by ribs and beams of stone that gave a greater sense of lightness to the building. In addition to these lighter supporting structures, so-called outer-wall archers were used to support the weight of the central nave's vault over the side nave ceilings.
These innovations made it possible to remove most of the sidewalls and replace them with tall narrow windows (lancet shaped) that were adorned with beautiful stained glass. This measure also allowed light to enter the environment, giving a new look to the religious temples, mainly because not only the white light of the sun, but also other colors resulting from the passage through the glass. Another characteristic stained glass window of the Gothic cathedrals was the rosettes placed above the entrance gates of the temples.
