What should you do for each company?

HOTSPOT
Your company named Contoso, Ltd. has a Microsoft Exchange Online subscription that uses a domain named contoso.com.
Contoso works with a partner company named A.Datum Corporation. A.Datum has an Exchange Server 2016 organization that uses a domain named adatum.com.
You need to ensure that users at Contoso can share their free/busy information with the users at A.Datum.
What should you do for each company? To answer, select the appropriate options in the answer area.
NOTE: Each correct selection is worth one point.
Hot Area:

Correct Answer:

Explanation/Reference:
References:
https://docs.microsoft.com/en-us/exchange/sharing/sharing
Manage mail flow topology 01