Research and media firm Youth Culture published Watch magazine, a teen publication given out free to high school students, but the publication was unable to deliver response rates to coupons or sample offers that its advertisers expected. Youth Culture handed out surveys to learn how students felt about the publication. Feedback indicated teen boys and girls were demanding very different things from the publication. This feedback was the gleaned from $\_\_\_\_\_$ data.

Select one:

a$.$

questionnaire

b$.$

internal secondary

c$.$

external secondary

d$.$

observational

e$.$

panel