A website listed ratings for a landscaping company from all customers who wanted to rate the company's services. After 20 customers rated the company, it had a rating of 4.5 stars. The website then stopped taking ratings.
Which statement is true?
a. The ratings are subject to selection bias, but not to participation bias.
b. The ratings are subject to participation bias, but not to selection bias.
c. The ratings are subject to neither participation bias nor selection bias.
