If a College Professor Surveyed His Students About Their Attitudes

Multiple Choice

If a college professor surveyed his students about their attitudes concerning the Social Security system and concluded that young adults doubt that they will ever receive Social Security benefits, his conclusion would be flawed because ​

A) his students were not a representative sample of young adults.
B) he did not survey the entire population of young adults. ​
C) he knew his subjects before he surveyed them. ​
D) his students were a random sample. ​