What is the meaning of the operation number in the routing?

What is the meaning of the operation number in the routing?
A . Similar to the BOM, it is only a sort sequence. The increment has no significance.
B. It determines the sequence in which the operations are processed. The increment contains time buffers (float before and after production).
C. It determines the sequence in which the operations are processed. The increment contains wait time and move time.
D. It determines the sequence in which the operations are processed. The increment has no significance.

Answer: B