(a) An authority may rent or lease housing only to persons of low income and only at rentals that persons of low income can afford, in accordance with policy guidelines to be adopted annually by the authority on or before the beginning of each fiscal year of the authority.
(b) An authority may not rent or lease housing to a tenant that consists of a greater number of rooms than the number the authority considers necessary to provide safe and sanitary housing to the proposed occupants without overcrowding.