Medium is a.
a way in which an artist creates a work of art.
b.
the material of a work of art.
c.
the use of more than one tool to create a work of art.
d.
made from ground up solids that contain color the color in paint.

An artwork's medium refers to the different materials or supplies that an artist utilizes in order to create a work of art. ... In painting, medium can refer to both the type of paint used (oil, acrylic, watercolor, etc) and the base or ground to which the paint is applied (canvas, wood, paper, etc).

Explanation:

c. landscape orientation