Which Role to choose for an User
<p>In an RBAC an User can have multiple roles. Say, an User named Abe is part of couple of Roles, Driver and Mechanic. Abe wants to check whether the truck needs an OilChange (an operation only Mechanics can do)</p>

<p>Option A) When Abe logs in to the application (mobile app or webpage), the backend authenticates Abe and determines that he has two roles. The application iteratively checks each of the Roles and see which Role has the permission to do that operation.</p>

<p>Option B) When Abe logs in to the application (mobile app or webpage), he choose the Role along with it. And backend authenticates Abe and uses the Role sent by Abe to check whether he has the permission to do that operation.</p>

<p>Or is there a better way to chose a Role for an action performed by the User? </p>

<p>Thanks.</p>