You have configured a new role for graphic designers at your company.

The Role Manager is a security tool that you can use to create and manage the roles that you want to assign to your security accounts (users and roles)1. To add multiple existing users to a role, you can use the Members tool in the Role Manager. This tool allows you to see a list of all the security accounts that are members of the role and add or remove users and roles as members of the role2. The other options are incorrect because:

The Security Editor is a security tool that you can use to assign the access rights that roles and users should have to the items in the content tree1. The Assign tool in the Security Editor is used to assign access rights to security accounts, not to add users to roles1.

The New button in the Role Manager is used to create a new role, not to add users to an existing role1.

The User Manager is a security tool that you can use to create and manage the users that have access to your system1. The New button in the User Manager is used to create a new user, not to add existing users to a role1. References: 21.