What is the cause of this behavior?

A user has written a playbook that calls three other playbooks, one after the other. The user notices that the second playbook starts executing before the first one completes.

What is the cause of this behavior?
A . Incorrect Join configuration on the second playbook.
B . The first playbook is performing poorly.
C . The steep option for the second playbook is not set to a long enough interval.
D . Synchronous execution has not been configured.

Answer: A