The commissioner of revenue shall, as hereinafter provided, certify to the state treasurer for payment, from that portion of the proceeds of the excise on cigarettes as authorized by paragraph (b) of section twenty-eight of chapter sixty-four C, the following:—

1. (a) From time to time when required, the contract assistance to the Massachusetts Bay Transportation Authority provided under section twenty-eight of chapter one hundred and sixty-one A or under other applicable laws, and from time to time when required, the contract assistance to regional transportation authorities, provided under section twenty-three of chapter one hundred and sixty-one B;

2. (b) From time to time, when required, reimbursements to cities and towns comprising transportation areas as provided under section one hundred and fifty-two A of chapter one hundred and sixty-one, and to the Woods Hole, Martha's Vineyard and Nantucket Steamship Authority, as provided under section nine A of chapter seven hundred and one of the acts of nineteen hundred and sixty, as amended;

   [There is no subsection (c).]