Final answer:
The correct answer is option 3. The Sainte-Chapelle is considered a masterpiece of the Rayonnant style, recognized for its radiant Gothic architecture, particularly its stained glass windows and detailed decoration. Built to house the Crown of Thorns, it exemplifies this particular phase of Gothic architectural development.
Step-by-step explanation:
The masterpiece of the Rayonnant style mentioned in the list is the Sainte-Chapelle. Built around 1248, it is renowned for its extensive use of stained glass and incredibly detailed Rayonnant Gothic architecture. This chapel was constructed under the orders of King Louis IX to house the Crown of Thorns, an important Christian relic. The style is characterized by a refinement of Gothic architectural elements, particularly the emphasis on windows that allow more light into structures and the decoration of every architectural surface.
Among the options provided, Sainte-Chapelle stands out for its architectural purity and the embodiment of the Rayonnant Gothic style. The other structures listed, such as Chartres Cathedral, Notre-Dame de Paris, and the Basilica of Saint-Denis, are exceptional examples of the Gothic style as well; however, they represent different phases within the Gothic period. The Basilica of Saint-Denis, for instance, is known for initiating the Gothic style during the time of Abbot Suger in the 12th century, while Chartres Cathedral is an example of the evolution of the Gothic style, transitioning from early to High Gothic. Notre-Dame de Paris is another monumental example of Gothic architecture but it's not specifically renowned for the Rayonnant style, unlike the Sainte-Chapelle.