Answer:
a. ground
Step-by-step explanation:
When drawing with graphite, the surface on which the drawing is created is called the ground. There is also a process of setting the ground to make the art better. This helps with more realistic shadows and having a better contrast.
The surface that is the ground will likely be light grey. It can be rougher or smoother, depending on the technique and preferences of the artists. There are many ways and techniques to set a ground, from with the normal graphite pencil or stick, to acrylic product set specifically for it.