While writing, by the client slice (N) and transcoding (M), co-generating N + M pieces of data, what is the maximum value of M in them?

The video cloud storage system also adopts Erasure Code to ensure data consistency and ensure the safety and reliability of data in massive data storage scenarios.

While writing, by the client slice (N) and transcoding (M), co-generating N + M pieces of data, what is the maximum value of M in them?
A . 5
B . 4
C . 2
D . 3

Answer: D