Q3. (20 points) the following table presents the lock requests by transactions T1, T2, and T3. S(. and X() stand for shared lock' and 'exclusive lock', respectively tl X(D) t2 t3 t4 t5 X(A) t6 t7 ime T1 T2 T3 X(C S(D Manager For the lock requests in the Table, determine which lock will be granted or blocked by the lock manager. Please write g' in the last row to indicate the lock is granted and 'b' to indicate the lock is blocked Give the wait-for graph for the lock requests in the above Table. Determine whether there exists a deadlock in the lock requests in the above Table, and briefly explain why