What do the three red tiles in the model of the equation below represent?

2 long x tiles and 3 square 1 tiles = 3 negative x tiles
–3
3
–3x
3x

Kilgore trout creates a new scale to diagnose depression. however, his scale only assesses one symptom of depression while ignoring others. which of the following is his new scale most likely lacking? a) test-retest reliability b) discriminant validity c) criterion validity d) alternate-forms reliability e) content validity f) none of the above