In Garmy et al. (2023), authors noted that the Clausson School Nurse Perception Questionnaire is a well-proven questionnaire. How do the authors demonstrate instrument validity?
a. Use of a content validity index (CVI)
b. Authors state that the instrument has high face validity
c. Use of correlational analysis to demonstrate concurrent validity
d. Garmy et al. (2023) do not use any of these approaches to demonstrate instrument validity