Explanation:

In Microsoft Sentinel, different built-in roles provide access at varying levels of capability, following the principle of least privilege.
* Microsoft Sentinel Responder
* Purpose: Designed for SOC analysts responsible for handling and responding to incidents.
* Capabilities:
* View and investigate incidents.
* Assign incidents, dismiss incidents, and change incident statuses.
* Respond to alerts but cannot modify Sentinel configuration or analytics rules.
* # This matches the requirements for User1, who needs to dismiss and assign incidents.
* Microsoft Sentinel Contributor
* Purpose: Intended for security engineers or Sentinel administrators.
* Capabilities:
* Create, edit, and delete analytics rules, workbooks, hunting queries, and automation rules.
* Manage data connectors and configuration.
* Cannot assign permissions but can change Sentinel resources.
* # This matches the requirements for User2, who must be able to modify analytics rules.
Other roles for reference:
* Microsoft Sentinel Reader: View-only permissions.
* Microsoft Sentinel Automation Contributor: Allows playbook and automation editing.
* Contributor/Reader: General Azure roles, not Sentinel-specific.