Final answer:
Modern art is characterized by the exploration of abstraction and non-traditional materials, breaking from past art traditions to create new styles that focus on emotional and psychological expression over physical realism.
Step-by-step explanation:
Among the options provided, Exploration of abstraction and non-traditional materials best characterizes modern art. Modern art is well-known for its spirit of experimentation and breaking away from the strictures of earlier art movements. Unlike Neoclassicism, which focused on clean lines and classical heroism, or Realism, which portrayed everyday life without idealization, modern art movements such as Impressionism, Abstract Expressionism, and Surrealism pushed the boundaries of traditional art by emphasizing abstraction, novel materials, and the emotional and psychological over the physical and realistic.
Abstract art was a significant component of modern art, with artists creating works that may not look 'real' but instead use colors, lines, and forms to evoke emotions and ideas. The period also saw other movements like Impressionism, which introduced radical changes in brushstroke techniques, color, and light utilization. Modern art was less about exact depiction and more about the essences of subjects, emotions, and artist's personal expression.