sculpture featured geometric shapes and planes and were constructed of industrial materials like plastic, metal and glass. He challenged conventional materials and techniques like carving, modeling, and casting. Most of his sculptures relied on the relationship of mass and space to suggest the nature of space-time. a. Futurism artist Umberto Boccioni b. De Stijl artist Naum Gabo c. Constructivism artist Naum Gabo d. Surrealism artist Umberto Boccioni