Final answer:
The most relevant piece of information for a fair housing complaint in the scenario described would be the client's use of a wheelchair, as it pertains to potential disability discrimination.
Step-by-step explanation:
If the Korean man decided to file a fair housing complaint regarding the landlord's refusal to conduct business with him based on the landlord's claim that he misrepresented his identity, the most relevant piece of information would be C- The client's use of a wheelchair. This information goes directly to the issue of potential discrimination based on disability, which is prohibited under fair housing laws.
The fact that the landlord refused to rent to him after discovering he was in a wheelchair could be seen as discriminatory behavior, as it suggests the landlord made a housing decision based on the man's disability rather than any legitimate concern about identity misrepresentation. Furthermore, the landlord's reaction upon meeting the man could potentially be seen as a pretext for discrimination against the man based on his use of a wheelchair.