What role does paragraph 1 play in the passage

• It introduces a common opinion that the rest of the passage challenges on the basis of scientific evidence.
• It explains why the passage focuses on actions people take individually rather than on actions people take as part of a group.
• It offers a specific example of a general principle discussed in the rest of the passage.
• It describes two phenomena, possible explanations of which are considered in the rest of the passage.

This is a multiple choice.