Whom do I put down on my complaint if I sue to get security dep. The agent who signed the lease or the compa

My security deposit has not been returned within the 21 days limit allowed by law. Whom do I sue--the part-owner by name who signed the lease when we moved in? Or, the part-owner who did the walk-through upon us moving out? Or, the name of the business as a whole without and reference to any particular individual?