For a scale that is measuring eating disorder likelihood to have good _______________, it needs to be able to differentiate between those who will get eating disorders versus those who will not.

A) external validity
B) interrater reliability
C) predictive validity
D) test-retest reliability

Predictive validity refers to the ability of a scale or test to accurately predict future behavior or outcomes. In this case, the scale is measuring the likelihood of developing an eating disorder, so it needs to be able to differentiate between individuals who will go on to develop an eating disorder and those who will not. Therefore, predictive validity is the most relevant and important type of validity for this scale. External validity refers to the extent to which the findings of a study can be generalized to other populations or settings, interrater reliability refers to the consistency of ratings across different raters or observers, and test-retest reliability refers to the stability of scores over time. While these types of validity and reliability are also important for a scale, they are not as directly relevant to its ability to accurately predict eating disorder likelihood.