Approximately, how long will these updates take to sync back to the Salesforce org?

Universal Containers (UC) usesHeroku Connect to synchronize changes to the Account object in their Salesforce org. UC’s Heroku application makes a batch update that changes one million records to the Heroku Postgres database table that mirrors the Account object.

Approximately, how long will these updates take to sync back to the Salesforce org?
A . It depends on the sync performance, which can vary from one connection to another.
B . 1 hour.
C . One million updates is too many for Heroku Connect to handle; therefore, the sync will fail
D . 12 hours.

Answer: A

Explanation:

https://devcenter.heroku.com/articles/using-sso-services-with-heroku#prerequisites-for-sso-with-heroku