3. Programming: Given two n-by-n matrices, A and B, write a shared memory OpenMP program to (a) (5 points) add the two n-by-n matrices to obtain matrix C (corresponding elements are added), and (b) (5 points) find the sum of all elements in C to yield global sum. OR Write a shared-memory OpenMP program for adding the numbers in array A[0..n-1], n=2k by giving either pseudo-codes or C codes. Assume p = 21 processes and that the answer should be in a shared variable global sum. For this, (a) Give the code for each process to find the start and end indices of the sub-array of array A to add sequentially. (b) Give the code for sequential add for each process in its own allocated portion. (c) Give the code here for each process to update the global sum without any race condition