Use the Distance Formula to determine whether the points $(7,9),(7,4)$ and $(7,7)$ are collinear.

A) $\text{ not collinear }$
B) $\text{ collinear }$

The primary purpose of the DSM is to:

A) help psychologists assess normal, as well as abnormal, behavior.
B) keep the number of diagnostic categories of mental disorders to a minimum.
C) provide descriptive criteria for diagnosing mental disorders.
D) describe the causes of common psychological disorders.