Which of the following is NOT an example of a survey?

• a.)
• A nutritionist is studying the relationship between eating carbohydrates and gaining weight. The nutritionist recorded the diets and weights of 10 people for a year.
• b.)
• Every 50th person listed in a neighborhood directory was emailed and asked about their favorite genre of music.
• c.)
• A cell phone company randomly called 200 customers and asked about customer satisfaction.
• d.)
• A high school student council is determining the new mascot for the school. Five students from each grade are asked what they would want as the mascot.