Denying one but not the other

[Nick Jensen]

We're about to rent a 2bd house. Two people applied as roommates. After running background checks via SmartMove, we feel that one person is qualified but the other isn't. We plan to send a denial letter (is email okay for this?) to the unqualified person, but what about the qualified person? Do we deny that person too because without the other roommate the rent would be too high for that one qualified person? Or do we accept the qualified person on the condition that they find another roommate, who we also must approve? 

Thanks for your time.

Nick