In terms of consideration of raw materials, which of the following is/are included in the guidelines of GMP? (I) Raw materials should be stored in properly labelled containers. (II) The materials should be sampled and tested with reference to the acceptance specifications. (III) The raw materials should be purchased in a cost-effective manner. (A) (I) only (B) (I) and (II) only (C) (II) and (III) only (D) (I), (II) and (III)