By default, which of the following windowing behavior does Dataflow apply to unbounded data sets?

By default, which of the following windowing behavior does Dataflow apply to unbounded data sets?
A . Windows at every 100 MB of data
B . Single, Global Window
C . Windows at every 1 minute
D . Windows at every 10 minutes

Answer: B

Explanation:

Dataflow’s default windowing behavior is to assign all elements of a PCollection to a single, global window, even for unbounded PCollections

Reference: https://cloud.google.com/dataflow/model/pcollection