Final answer:
Flying buttresses eliminated the need for thick, massive walls in Gothic architecture, enabling thinner walls with larger windows and more interior light.
Step-by-step explanation:
Flying buttresses, an architectural innovation of the Gothic era, eliminated the need for thick, massive walls previously used in Romanesque architecture to support heavy roof structures.
These flying buttresses were essential in transferring the lateral thrust and weight of the roofs and upper stories away from the walls and directing them to the ground. As a result, the walls could be built higher and thinner, enabling larger windows and more light to fill the interior spaces.
Consequently, the installation of flying buttresses allowed for the expansive use of stained glass in Gothic cathedrals, enhancing both the physical light within the structure and the metaphorical idea of divine light. Given the choices provided, flying buttresses essentially made the heavy and thick walls of earlier architectural styles irrelevant, enabling the pointed arches, ribbed vaults, and spired towers characteristic of the Gothic style.