Which Question Below Is an Example of a Background Question

Which question below is an example of a background question?

A) "Can you provide an example of a time when you developed a highly effective ad campaign?"
B) "Suppose a coworker with more experience was not following standard work procedures. What would you do?"
C) "What steps would you follow to conduct a brainstorming session with a group of employees on safety?"
D) "What is the procedure you would follow when examining a patient complaining of chest pain?"
E) "What experience and training have you had with drafting designs for commercial buildings?"