Scott took a part time job as a pollster for the Stonebridge Mall. He was assigned to stand at the west entrance of the mall and approach every 25th person coming into the mall to ask a few questions. While counting the people who passed by, he skipped everyone that he knew. Identify the one piece of information that might be a source of bias.

A.He stood at the west entrance of the mall.
B.He only asked every 25th person.
C.He only approached people coming into the mall, not those going out.
D.He skipped everyone that he knew.

Question

Scott took a part time job as a pollster for the Stonebridge Mall. He was assigned to stand at the west entrance of the mall and approach every 25th person coming into the mall to ask a few questions. While counting the people who passed by, he skipped everyone that he knew. Identify the one piece of information that might be a source of bias. 

A.He stood at the west entrance of the mall.  
B.He only asked every 25th person.  
C.He only approached people coming into the mall, not those going out.  
D.He skipped everyone that he knew.