Cognito Sync is an AWS service that you can use to synchronize user profile data across mobile
devices without requiring your own backend. When the device is online, you can synchronize
data. If you also set up push sync, what does it allow you to do?

A.
Notify other devices that a user profile is available across multiple devices

B.
Synchronize user profile data with less latency

C.
Notify other devices immediately that an update is available

D.
Synchronize online data faster

Explanation:
Cognito Sync is an AWS service that you can use to synchronize user profile data across mobile
devices without requiring your own backend. When the device is online, you can synchronize
data, and if you have also set up push sync, notify other devices immediately that an update is
available.
http://docs.aws.amazon.com/cognito/devguide/sync/