Question 4 (20 points) Consider two transactions T and U on simple integer objects i and j: T: x = read(i); write(), 44); U : write(i, 44); write(j,66); and an initial state of the system with i = 10, j = 20. For each of the interleavings of T and U shown below, answer: (3 pts.) for each interleaving: is the interleaving serially equivalent? (2 pts.) for each interleaving: could the interleaving occur with two-phase locking? If so, show the possible placement of the exclusive lock statements lock(i), lock(j), unlock(i), and unlock(j) in the interleaving. T U U x= read(i); T x = read(i); write(j, 44); (a ) write(i, 44); (b) write(j, 44); write(j,66); write(i, 44); write(j,66); T T U write(i, 44); write(j,66); U write(i, 44); (C) (d) X = readi); T = write(), 66); read(i); write(j, 44); write(j, 44)