In utilizing the rental assistance payments authority pursuant to subsection (a)(2)—
(A) the Secretary shall make such assistance available in existing projects for units occupied by low income families or persons to extend expiring contracts or to provide additional assistance when necessary to provide the full amount authorized pursuant to existing contracts;
(B) any such authority remaining after carrying out subparagraph (A) shall be used in projects receiving commitments under section 1484, 1485, or 1486 of this title after fiscal year 1983 for contracts to assist very low-income families or persons to occupy the units in such projects, except that not more than 5 percent of the units assisted may be occupied by low income families or persons who are not very low-income families or persons; and
(C) any such authority remaining after carrying out subparagraphs (A) and (B) may be used to provide further assistance to existing projects under section 1484, 1485, or 1486 of this title.