Any employer against whom liability may exist for compensation under this Act shall upon the order and direction of the Commission:
(a) Deposit the commuted value of the total unpaid compensation for which such liability exists, computed at 3% per annum in the same manner as provided in Section 9, with the State Treasurer, or county treasurer in the county where the accident happened, or with any savings and loan association or State or national bank or trust company doing business in this State. Any such depositary to which such compensation may be paid, shall pay the same out in installments as in this Act provided, unless such sum is ordered paid in, and is commuted to a lump sum payment in accordance with the provisions of this Act; or(b) Purchase an annuity, in an amount of compensation due or computed, under this Act within the limitation provided by law in any insurance company granting annuities and licensed or permitted to do business in this State which may be designated by the employer or the Commission.