Configure Azure AD External Identities Pricing

C.

The correct answer is C. a linked subscription.

Explanation:

Azure AD External Identities allows organizations to provide secure access for external users (such as partners, customers, or contractors) to their applications, services, and resources. By default, Azure AD External Identities pricing is based on the number of authentication attempts, which includes both successful and unsuccessful attempts.

However, if you want to change the pricing model to be based on monthly active users (MAU), you need to configure a linked subscription. A linked subscription is a billing agreement that links an Azure subscription to an Azure AD tenant. When you create a linked subscription, you can choose the billing model you want to use for Azure AD External Identities, such as per authentication or per monthly active user.

To configure a linked subscription for Azure AD External Identities, follow these steps:

1. Sign in to the Azure portal with an account that has global administrator or billing administrator permissions.

2. In the left-hand menu, click on "Azure Active Directory."

3. In the Azure AD menu, click on "External Identities."

4. In the External Identities menu, click on "Pricing."

5. Click on "Add subscription" to create a new linked subscription.

6. Follow the prompts to create the linked subscription, including selecting the billing model you want to use.

After you have created the linked subscription with the desired billing model, you can start using Azure AD External Identities with the new pricing model based on monthly active users (MAU).

Therefore, the correct answer is C. a linked subscription.