A local restaurant wants to estimate the proportion of customers that are satisfied with the service and food. Which of the following
samples will likely not be blased because of random sampling?

A. As customers leave, have the manager flip a coin. If it is heads, have the customer fill out a survey. If it is tails, do not give the
customer a survey.

B. Have a survey included on the back of the receipt that customers can fill out.

C. Give customers a web address that has a survey and let them know that if they fill it out, the get a free dessert on their next visit.

D. Ask the first 100 customers of the day.