A U-shaped long-run average cost curve is based on the assumptions that:

(A) Greater division of labour and specialisation accure to larger firms

(B) Minimum cost of production at various levels of output

(C) Economies of scale prevail at small levels of output

(D) It becomes more difficult to manage the firm effectively as it grows bigger

(E) Diseconomies of scale prevail at larger level of output

Choose the correct answer from the options given below: