One criticism of the DSM noted by your author is that it adheres to a categorical model, which means that a person is seen as either having a mental disorder, or not having a mental disorder. There is little or no allowance for "degrees" of a disorder.
Answer: Option B
Explanation:
The criticism of DSM is that it is categorical wherein a person is categorized on the basis of whether or not the person has come mental disorder. The degree of the mental disorder does not play any role in the categorization of the person.
The DSM is a publication that is a classification of mental disorders. As per this publication, a person is seen as either having a mental disorder or not having the mental disorder. People with same type of mental disorder are categorized in the same manner irrespective of how much the disorder impacts the person.