Consider the following rules of the network diagram and state which of them are correct:(i) Network always has a single initial and final event.(ii) An event can occur twice.(iii) No activity can start until its tail end event has occurred.(iv) It is usual practice to show time flow from right to left.

• A. (i), (ii) and (iii)
• B. (i) and (iii)
• C. (i), (iii) and (iv)
• D. (i), (ii), (iii) and (iv)