Which of the following descriptions of the Region concept in Huawei Cloud Stack is wrong?

Which of the following descriptions of the Region concept in Huawei Cloud Stack is wrong?
A . Region belongs to the regional concept of L0 layer, that is, geographical area
B . The management planes in the region are interconnected, and some high-security services can be deployed in a separate region.
C . If the latency between physical data centers exceeds 100ms, they need to be planned into different regions.
D . Region is a circle with delay as radius

Answer: C