A North Carolina real estate broker is managing an apartment community.  occupancy has dropped by 80% and the broker needs to attract more tenants. Which  of the following actions made a broker lawfully make to solicit more tenants?

A. Offer 1 months free rent for existing tenants who refer new tenants

B. offer 2 months free rent to each new tenant who signed a one-year lease

C. Offer referral fees to the Chamber of Commerce for sending new tenants

D. Offer referral fees to any broker who has an active or inactive license