Which of the Following Description About the Huawei Oceanstor 9000

Which of the following description about the Huawei Oceanstor 9000 to achieve N + M redundancy technology is wrong?

A) Huawei Oceanstor 9000 can configure different data protection levels for different directories / files.
B) Data written to Huawei OceanStor 9000 system will be divided according to the size of 4G chunk.
C) Every N chunk, according to Erasure code algorithm to calculate M chunk calibration fast.
D) The utilization of protected data space is about N / (N + M) , the reliability of the data is determined by the value of M, the greater the M is, the higher the reliability.