Experiments on Mail Questionnaires for Census of Population Revealed What

Multiple Choice

Experiments on mail questionnaires for census of population revealed what about questionnaire form and layout?

A) Instructions printed in red made little difference except that they made the questionnaire appear more complicated to the respondents.
B) Sensitive information placed at the end of the questionnaire was answered more frequently than sensitive information placed elsewhere.
C) Questions at the top of the page received more attention than those placed at the bottom.
D) Both A and C are correct.