Bricolage is an unusual art form because it is formed of materials such as knickknacks and cast-offs not usually employed by fine artists.

A. because it is formed of materials such as knickknacks and cast-offs

B. because it is formed of materials like knickknacks and cast-offs that are

C. because it is formed of materials, like knickknacks and cast-offs, materials

D. in that its formation, materials such as knickknacks and cast-offs, is

E. in that it is formed of materials such as knickknacks and cast-offs, materials