Say if the statement is TRUE or FALSE: 1. The worst-case running time of MergeSort is bigger than its average case running time. 2. The Big-Oh notation O(n) gives an upper bound of the running time of algorithms. 3. In the QuickSort algorithm, choosing randomly the pivot allows to give a probabilistic guarantee on the average running time of the algorithm to be O(n ln(n)) 4. The MergeSort of an array of size n has a recursion tree which structure depends on the initial ordering of the elements in the array.