Questions: This innovation made the huge areas of stained glass in the Gothic cathedral possible. thick barrel vaults heavy columns of masonry steel reinforcements flying buttresses

The answer is flying buttresses.

Thick barrel vaults are characteristic of Romanesque architecture, which preceded the Gothic style. They are not conducive to large stained glass windows because they require thick walls to support the weight of the roof.

While heavy columns can support large structures, they do not specifically enable the creation of large stained glass windows. Instead, they would limit the amount of wall space available for windows.

Steel reinforcements were not used in Gothic cathedrals, as steel was not commonly used in construction until much later. Gothic architecture relied on stone and other materials available at the time.

Flying buttresses are a key innovation of Gothic architecture. They transfer the weight of the roof and upper walls away from the building and onto external supports, allowing for thinner walls and larger windows. This structural innovation made it possible to incorporate large areas of stained glass, which are a hallmark of Gothic cathedrals.