Veterinarians often use non-steroidal anti-inflammatory drugs to treat lameness in horses. A group of veterinary researchers wanted to find out how widespread the practice was in the United States. They obtained a list of all veterinarians treating large animals, including horses. They sent questionnaires to all the veterinarians on the list. Such a survey is called a census. The response rate was 40%. Which of the following statement is correct?
A. The sample consisted of all veterinarians on the list and therefore equaled the target population.
B. The sample consisted of all veterinarians who returned the questionnaire.
C. The sample consisted of all veterinarians who treat horses with NSAIDs.
D. None of the choices are correct.