Let A[1,,n] be an array of n distinct numbers. If iA[j], then the pair (i,j) is called a reverse pair for A. (a) List the five reverse pairs of the array A=[2,3,8,6,1]. (b) What is the relationship between the running time of INSERTION_SORT and the number of reverse pairs in the input array? Justify your answer. (c) Modify Merge_SORT in order to give an algorithm which determines the number of reverse pairs in an array of n numbers in (nlogn) run time. Fully explain your algorithm and also justify why your algorithms satisfies the required time complexity bound