What happens next in this paragraph?

They grease large pans and pour the different colored batter into them. They put the pans into an oven. They set the timer on the oven. they
Choices:
+frost the cake with blue frosting and add sprinkles.;
+pour boiling water into the pan and melt the batter.;
+then add a cake to the cake.;
+add more batter before measuring and printing the cake.;
frost the cake with blue frosting and add sprinkles.