a. A survey of teenagers about their favorite colors
b. A survey of students about vacation policies in a school district
c. A survey of supermarket shoppers about products they would like to see added
d. A survey of bike riders on whether they wear helmets
Answer:- b. A survey of students about vacation policies in a school district
Step-by-step explanation:
Biased since of what they would want not generally school. This survey possibly will be affected by bias, since students may have a preference for longer set. a survey of students about vacation policies in a school district.