a. The content of the matrix Need isP0（0 0 0 0） P1（0 7 5 0） P2（1 0 0 2） P3（0 0 2 0） P4（0 6 4 0）.
b. The system is in a safe state because the Available matrix is equal to（1 5 2 0），Process P0 and P3 can run, when the process of running P3 finished, it releases its resources, while allowing other processes to run.
c. Can be satisfied, the Available matrix is equal to (1 1 0 0), and the operation can be completed when running in the order P0, P2, P3, P1, P4.