Art Deco is primarily characterized by which of the following features?

Art Deco is characterized primarily by its streamlined, elongated, and symmetrical design, which reflects the era's embrace of modernity and industrial advancement. This style emerged in the 1920s and 1930s and is known for its bold, geometric forms and the use of materials like chrome, glass, and concrete that evoke a sense of luxury and progress. The emphasis on symmetry and clean lines in Art Deco design was a departure from the ornate and intricate styles that preceded it, making it distinct and easily recognizable.

In contrast, flowing lines and flat shapes are more typical of other art movements, such as Art Nouveau. A realistic portrayal of everyday life is more aligned with movements like Realism or Impressionism, which focus on capturing scenes from life as they are. Optical effects and illusions are more commonly associated with modern movements such as Op Art. Therefore, the streamlined, elongated, and symmetrical elements define the essence of Art Deco, capturing the spirit of its time and making option B the correct choice.