Jane sets up an experiment to find out if kittens prefer skim milk, 2% milk, or whole milk. she puts out a cup of skim milk for 5 kittens and then measured how much the kittens drank during a day. the next day, she used the same kittens and put out a cup of 2% milk. the last day, she used the same kittens and put out a cup of whole milk. she discovered that the kittens preferred whole milk. there are many problems with this experiment. each of the following would improve the experiment except which one?