You are building an e-commerce web app and plan to use Azure Key Vault so App Service authentication with Azure AD secures sign-ins. What should you enable on the e-Commerce Web App to allow it to access Key Vault securely?

Enabling Managed Service Identity (MSI) for the e-commerce web app is the correct approach. MSI provides an automatically managed identity for Azure services, allowing them to authenticate to services like Azure Key Vault without requiring developers to manage credentials. This enhances security by removing the need to store secrets in code or configuration files. Running the az keyvault secret command is a CLI operation for managing secrets, not a configuration for the web app itself to access Key Vault. Azure AD Connect synchronizes on-premises directories with Azure AD and is unrelated to an Azure web app accessing Key Vault. Creating an Azure AD service principal is an alternative for non-Azure services or scenarios where MSI isn't suitable, but for an Azure App Service, MSI is the more secure and simpler option.