Choice of medium allows the artist to
a. convey different messages.
b. experiment with combining materials to create new media.
c. reconnect with old forms of art.
d. improve realism in art, particularly with portraits

a. convey different messages.

Explanation:

An artist can make use of varied media to express the message that he or she wants to communicate to the audience. The choice of the medium significantly impacts the way the art form is perceived by the public.For example, a bright painting on a shiny canvas presents a message which is different from the same painting made using dull colours on a worn out piece of paper.

variety in color and variety in texture