At the beginning of the project, Scratchy will ask you to answer all of the possible options. Do this by listing one option each time you are asked. You may repeat an answer, such as if you were choosing a random number from the set {1,1,2,3,5}. You will be asked until you give an empty answer. When you are done, Scratchy will choose a random option from among the ones listed and tell it to you.
If you have any questions about how this works just ask in the comments.