Which design changes are required to the architecture to meet the requirements for both tenants?

An administrator maintains multiple tenants on a vRealize Automation environment. Consumers of Tenant B have requested to modify their current tenant architecture from the default to incorporate their own mail servers so that their user base can respond to notifications for completing work items and approvals. Consumers of Tenant A insist that no change be made to their current mail settings.
Which design changes are required to the architecture to meet the requirements for both tenants?
A. Log in to the default tenant as administrator and under the Administration tab, select Email Servers, then add and configure the additional new mail servers.
B. Log in to Tenant B as a tenant administrator and under the Administration tab, select each mail server and click Override Global, then configure the requested new mail servers.
C. Log in to the default tenant as administrator and under the Administration tab, select Tenant B, then add and configure the requested new mail servers for the tenant.
D. Log in to Tenant B as an IaaS administrator and grant approval administrator privileges to the required user base of the tenant.