What would be a good prequalifying question to ask?

You meet a customer for the first time. They explain that their current environment for NAS does not meet their needs. You want to make sure that Isilon is a good fit for their needs.

What would be a good prequalifying question to ask?
A . What protocols are accessing your NAS?
B . What application are you using to create directories?
C . Is your datacenter ISO9001 compliant?
D . How many users are in your Directory Services?

Answer: A