Final answer:
Grant Wood's American Gothic is the artwork that is realistic, objective, and representational, in contrast to the other mentioned works which are more abstract.
Step-by-step explanation:
Among the artworks mentioned, Grant Wood's American Gothic from 1930 is the one that can be characterized as realistic, objective, and representational. This painting is part of the Regionalist movement, which focused on a heroic and positive image of the American Heartland, portraying everyday scenes and people with a sense of idealism and straightforward representation. On the other hand, the other works mentioned such as Judy Pfaff's Voodoo, and avant-garde pieces by artists like Picasso and Balla, lean more towards abstraction and do not fit the criteria for realistic and representational art as clearly as Wood's work does.