Explanation:

Box 1: Yes
Invitations can only be sent to outlook.com. Therefore, User1 can accept the invitation and access the application.
Box 2. Yes
Invitations can only be sent t o outlook.com. However, User2 has already received and accepted an invitation so User2 can access the application.
Box 3. No
Invitations can only be sent to outlook.com. Therefore, User3 will not receive an invitation.
Based on the Microsoft SC-300: Id entity and Access Administrator Study Guide and Microsoft Learn module
"Manage external collaboration settings in Azure AD", Azure Active Directory provides granular control over external collaboration through External collaboration settings and Collaboration restrictions. These settings control which external domains can receive guest invitations.
1# # Collaboration Restrictions Setting The configuration in the exhibit shows:
"Allow invitations only to the specified domains (most restrictive)"
Target Domain: Outlook.com
This means invitations can only be sent to users whose email domains are explicitly listed (in this case, Outlook.com). Any other external domain (like fabrikam.com or adatum.com) is not permitted to receive or accept invitations.
2# # Evaluating Each User [email protected]
* Domain Outlook.com is listed under allowed domains.
* Although the invitation was initially not accepted , since the domain is allowed, User1 can accept the invitation and gain access. # Answer: Yes [email protected]
* The domain fabrikam.com is not listed in the allowed domains list.
* However, this user already accepted the invitation before the restriction was configured.
* Once a guest has accepted the invitation, they are an existing guest object in Azure AD and retain access unless explicitly removed. # Answer: Yes [email protected]
* Domain adatum.com is not listed under allowed domains.
* Therefore, this user cannot receive or accept new invitations for collaboration resources like SharePoint Online. # Answer: No Summary from Microsoft documentation:
"When collaboration restrictions are set to allow invitations only to specified domains, invitations to all other domains are blocked. Existing guest users who have already accepted invitations remain unaffected." ( Source: Mic rosoft Learn - Configure external collaboration settings in Azure AD )