See the solution below in Explanation.
Explanation:
To create a retention policy for Microsoft Teams that meets the specified requirements, follow these steps:
* Sign in to the Microsoft 365 compliance center:
* Log in to the Office 365 Admin Portal.
* Visit the Microsoft 365 compliance center.
* Navigate to Retention Policies:
* Select Policies, then click on Retention.
* Create a New Retention Policy:
* Click on New retention policy.
* Provide a Name for your new retention policy (e.g., "Sales Teams Retention Policy").
* Optionally, add a Description.
* Select the Location:
* Choose the location to which the policy will be applied. In this case, select Microsoft Teams.
* Configure Retention Settings:
* Set the retention period to 5 years from the date items are created.
* Specify whether you want to retain or delete the content after the retention period.
* Apply the Policy:
* Save your changes.
This policy will now apply to Microsoft Teams chat and channel messages for users with a department attribute of "Sales," retaining items for five years before automatic deletion

See the solution below in Explanation.
Explanation:
To restrict the Confidential - Finance label to only the members of the Finance Team group, follow these steps:
* Create a Sensitivity Label:
* Log in to the Microsoft Purview portal or the Microsoft Purview compliance portal as an admin.
* Navigate to Sensitivity labels and create a new label called "Confidential - Finance".
* Specify the appropriate settings for this label, including encryption, content markings, an HYPERLINK
"https://learn.microsoft.com/en-us/purview/sensitivity-labels"d permissionsHYPERLINK "https://learn.
microsoft.com/en-us/purview/sensitivity-labels"1.
* Configure Encryption Settings:
* When creating the label, ensure that you configure the encryption settings.
* Choose either to assign permissions no HYPERLINK "https://learn.microsoft.com/en-us/purview
/sensitivity-labels"w (where you determine exactly which users get which permissions) or allow users to assign permissions when they apply the label to contentHYPERLINK "https://learn.microsoft.com
/en-us/purview/encryption-sensitivity-labels"2.
* Assign the Label to the Finance Team Group:
* In the Microsoft Purview portal, go to the Groups section.
* Select the Finance Team group.
* Under Settings, choose Sensitivity labels.
* Add the "Confidential - Finance" label to this group.
* Only members of the HYPERLINK "https://learn.microsoft.com/en-us/purview/sensitivity-labels" Finance TeamHYPERLINK "https://learn.microsoft.com/en-us/purview/sensitivity-labels" will now have access to this labelHYPERLINK "https://techcommunity.microsoft.com/t5/security-compliance- and-identity/general-availability-microsoft-information-protection/ba-p/1497769"3.
* Test the Configuration:
* Verify that only members of the Finance Team can apply the "Confidential - Finance" label to documents, emails, or other content.

Reference:
https://docs.microsoft.com/en-us/microsoft-365/compliance/classifier-get-started-with?view=o365-worldwide