Gathering information from customers about a problem with their Apple

Which of the following would be the most appropriate question to ask FIRST, when gathering information from customers about a problem with their Apple product?
A. What is the issue?
B. What operating system are you using?
C. Did you turn off the computer improperly?
D. What steps have you taken to resolve the problem yourself?
[toggle title_open=”Close Me” title_closed=”Answer” hide=”yes” border=”yes” style=”default” excerpt_length=”0″ read_more_text=”Read More” read_less_text=”Read Less” include_excerpt_html=”no”]A[/toggle]