Which of the following is more likely to be the source for problems in this survey?
A.
This survey is tilted in favor of local alcohol distributors, who have a conflict of interest with online sellers.
B.
The data collection and analysis are not scientific and logical.
C.
Subjects are not sampled in a right way and can not represent the whole American teenage population.
D.
The survey results are affected by gifts to subjects, which can be misleading.