Write the next sentence in this paragraph:

How to prevent baking a lumpy cake
Place oven rack so cake pan will be baking near the center of your oven so the hot air can circulate fully.
Make sure rack is level.
Preheat oven.

Choices: a). Allow cake pan to fully preheat before adding butter to the pan. Butter is great for mashing, which can cause cake batter to stick to oven surfaces. b). Prepare your pans by lining the bottom with parchment paper or waxed paper. Trace the pan on top of the paper you are using, then cut on the line. c). The oven must be preheated to 200 f (93 c) or range. If oven-bottom is below 200 f (93 c) for cake pans, wait a few minutes, or turn the rack counter clockwise from the oven. d). If you prefer board pan ovens, the best guidelines are placing them at about 400 f (204 c). Place cake pan in oven preheated to about 350 f (177 c).
b).