The licensing requirements can be met by creating three distinct groups based on the user populations and their specific license needs.

1. Group 1 (All Users): This group will contain all users (User1, User2, User3, User4, User5). It will be assigned the Office 365 E3 license (with the Power Automate service plan disabled) and the Enterprise Mobility + Security E5 license. This fulfills the two requirements applicable to everyone.

2. Group 2 (Research Department): This group will contain only the research users (User1, User3, User5). It will be assigned the Power BI Pro license.

3. Group 3 (Marketing Department): This group will contain only the marketing users (User2, User4). It will be assigned the Visio Plan 2 license.

This three-group structure correctly assigns all required licenses and logically separates the common "base" licenses from the department-specific "add-on" licenses, representing the most efficient and scalable management approach.

A. 1: A single group cannot be used, as it's impossible to selectively assign the Power BI Pro and Visio licenses to only specific members within that one group.

B. 2: Using only two groups (e.g., one for Research and one for Marketing) would require assigning the common licenses (O365 E3 and EMS E5) to both groups, creating redundant management.

D. 4: Four groups are unnecessary. The two licenses required by all users (Office 365 E3 and EMS E5) can be efficiently assigned to a single "all users" group.

E. 5: Five groups are excessive. There are only three distinct licensing policies required for the specified user populations (All Users, Research, and Marketing).

1. Microsoft Entra documentation

"What is group-based licensing in Microsoft Entra ID?": This document outlines the core principles. It states

"You can assign one or more license products to a group." This supports assigning both Office 365 E3 and EMS E5 to a single "All Users" group. It also explains that a user who is a member of multiple groups inherits the union of all assigned licenses

which is the principle that makes the three-group solution work. (See the section "How does group-based licensing work?").

2. Microsoft Entra documentation

"Assign licenses to users by group membership in Microsoft Entra ID": This guide provides scenarios for license management. The examples illustrate the best practice of using a base group for common licenses and then layering additional licenses for specific user sets via other groups

which directly supports the three-group answer. (See the section "Group-based licensing scenarios").

3. Microsoft Entra documentation

"Group-based licensing additional scenarios": This document details more complex situations

including how the system resolves license conflicts when a user is in multiple groups. The principle of license inheritance (union of services) is foundational to the solution requiring separate groups for separate license assignments. (See the section "Use multiple groups to manage licenses").