A student covered his pot with glaze and it stuck to the shelf after firing. What should he have done to prevent this from happening?

A.
Wedge the clay more thoroughly.
B.
Apply a coat of slip over the glaze.
C.
Make sure there is no glaze on the bottom of the pot.
D.
Make sure the kiln was fired to the correct temperature.

C. Make sure there is no glaze on the bottom of the pot.