73. In order to synthesize the final product shown below, predict when should a protecting group be added and when should it be removed? (A) The hydroxyl group should be protected before step I and removed after step I (B) The hydroxyl group should be protected before step I and removed after step II (C) The hydroxyl group should be protected before step I and removed after step III (D) The hydroxyl group should be protected before step II and removed after step III (E) There is no need for a protecting group in this synthesis.