Under What Condition Should a Kuder-Richardson (KR-20)coefficient Be Used to Establish

Under what condition should a Kuder-Richardson (KR-20) coefficient be used to establish the internal consistency of an instrument?

A) When questions are open-ended
B) When questions or statements require a yes or no response
C) When the instrument uses a Likert-type response scale
D) When the instrument is designed to measure more than one concept