The cafeteria chef for a company wants to know about how many of the employees are vegetarians. Which sampling method will result in a sample that is NOT biased?

AHe questions every employee in the advertising department who is exiting a meeting.

BHe obtains a list of employee names and numbers and calls every fifth person on the list.

CHe puts notices in the break rooms asking employees to e-mail him if they are a vegetarian. d) He asks every other employee he sees in the cafeteria for breakfast about food preferences...

DHe asks every other employee he sees in the cafeteria for breakfast about food preferences...