This principle is defined as: "The difference in quality between two instances of an art element, or using opposing
qualities next to each other."
Balance
Contrast
Pattern
Symmetry

It increased the value of original works of art.

The answer is a just took the test

Yes because in graphic design you add elements of art into one piece and/or program. although, you place together graphic designs on a computer,  you still have to know about the principles of design which is included in art.