Professor Duncan Administered a Questionnaire Containing the Following Items: Please

Multiple Choice

Professor Duncan administered a questionnaire containing the following items: Please tell me how you feel about your supervisor's leadership style on the following three items: 1 2 3 4 5
Duncan was using a:

A) Semantic differential scale.
B) Thurstone scale.
C) Bogardus social distance scale.
D) Guttman scale.
E) Likert scale.