RAID System calculating XOR operations

A). What level RAID system is this? RAID0, RAID1, RAID2, RAID3, RAID4, RAID5 or RAID6?

B. )Writing a new block 8 requires reading some number of disk blocks (=R), writing some number of disk blocks (=W) and performing some number of XOR operations (=N). For example, computing A xor B xor C would be considered 2 XOR operations. What are the values for R, W and N? Explain your answer.

Block 0 Block 5 Block 10 Block 15 P16-19 Block 1 Block 6 Block 11 P12-15 Block 2 Block 7 P8-11 Block 3 PO-3 P4-7 Block 8 Block 13 Block 9 Block 14 Block 19 Block 12 Block 16 Block 17Block18 Block 0 Block 5 Block 10 Block 15 P16-19 Block 1 Block 6 Block 11 P12-15 Block 2 Block 7 P8-11 Block 3 PO-3 P4-7 Block 8 Block 13 Block 9 Block 14 Block 19 Block 12 Block 16 Block 17Block18