Read the following passage and select the most appropriate answer : Nine books are to be arranged from the left to right on a shelf . Of these , four books are leather -bounds , three are cloth -bounds and remaining books are paperbacks. The leather bound books must be together . The paperback books must also be together. The cloth-bound books need not to be together . The cloth-bound books must be next to each other , if a paperback book is in which of the following position ?