20.—The Board shall, in each year, carry out such examinations as it considers appropriate for the purpose of ascertaining—

(a) whether and to what extent the resources of the Board—

(i) have been used, and

(ii) if acquired or disposed of by the Board, have been so acquired or disposed of,

economically and efficiently, and

(b) whether any such disposal has been effected upon the most favourable terms reasonably obtainable.