This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to cool cakes
Decide how much time you have.
Depending on the type of cake, cooling using this method can be done in just a couple of hours. Here are some things to consider :
Angel food cakes, pound cakes, sponge cakes and other light and fluffy cakes can cool in the refrigerator in about 1-2 hours.

Pick your answer from:
i. They are put back up to room temperature within 15 minutes, and rise in an hour. Choose the right type of cake: either natural, dry, pre-processed, frozen or certified.;
ii. Powdered cakes, cream cakes, frosts and cakes with cream Cool the cake. Place the cake on a flat surface in the refrigerator.;
iii. This method may not be the best choice for a cheesecake, as quick changes of temperature can upset the structure of the cake, causing cracks. For rich, creamy cakes that are served chilled, this method may take you up to 4 hours.;
iv. The exact amount of time you want to leave the cakes are totally up to you. You can leave them for up to several days, giving you a longer cooling time, but if you need to allow them to cool, boiling is recommended.;
The answer is:
iii.