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:
Valuable
----:----:----:----:----
Worthless
Easy
----:----:----:----:----
Demanding
Critical
----:----:----:----:----
Uncritical
Duncan was using a:

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