Alyson is experiencing severe anxiety. Her psychiatrist attributes her disorder to a chemical imbalance. Her psychiatrist is using the model of abnormality.

If the age of the lowermost layer of a rock sample is more than 2 million years, which of the following could be the age of the upper layers? less than 1 million greater than 3.5 million between 2 million and 3 million between 3 million and 3.5 million