When discussing the business requirements of a WLAN design, what is the first question that should be posed

The first question should be "What is the purpose of WLAN ?" .

In order to design a stable and better WLAN user should understand the purpose or intended use of WLAN.

For example : A school's wireless  network will be different than the corporate wireless network.

In order to design the WLAN in a better way . User should know following

1. What is the purpose of the WLAN ?

2. How many users will be using it at a time ?

3. How many users will use it over all given a period of time ?

4. What are the common applications being used ?

5. Who will be using the WLAN?

6. Is there any legacy devices that need backward compatibility ?

So unless user doesn't understand the complete purpose and requirement of the WLAN, it is not possible to give the best design for the same. Capacity and Coverage needs to be taken care while designing WLAN.

Explanation:

as explained above.