Which of the following is the wrong description about Flink barrier?

Which of the following is the wrong description about Flink barrier?
A . The barrier is periodically inserted into the data stream and flows as part of the data stream.
B . The barrier is the core of the Flink snapshot.
C . A barrier separates the data of this cycle snapshot from the data of the next cycle snapshot.
D . When the barrier is inserted, the data stream is temporarily blocked.

Answer: D