a. A write of one block of data requires the following: read of theparity block, read of the old data stored in the target block,computation of the new parity based on the differences betweenthe new and old contents of the target block, and write of theparity block and the target block.b. Assume that the seven contiguous blocks begin at a four-blockboundary. A write of seven contiguous blocks of data could beperformed by writing the seven contiguous blocks, writing theparity block of the first four blocks, reading the eight block,computing the parity for the next set of four blocks and writingthe corresponding parity block onto disk.