Which sharing option should be created to allow 'Customer Manager' role access to cases owned by 'Support Manager' role users?

The ownership-based sharing rule is the most appropriate choice for allowing users in the 'Customer Manager' role to access cases owned by users in the 'Support Manager' role. This type of sharing rule specifically grants access to records based on the ownership of those records. By establishing a sharing rule based on ownership, you can extend visibility and access rights to case records that are managed by certain users or roles, in this case, those that are owned by the 'Support Manager' role.

This ability to configure sharing based on ownership is particularly crucial in scenarios where the organization wants to ensure that certain roles can collaborate on specific cases or records without compromising data security and privacy norms inherent in the platform. Thus, leveraging ownership-based sharing rules enables tailored access control while supporting effective collaboration among roles that require it.

The other options, while valid in their contexts, would not effectively achieve the necessary sharing requirements as specified in the question. Criteria-based sharing rules depend on specific field values rather than ownership, Super User Access involves elevated privileges that are not specific to role-based sharing, and public group sharing does not directly link access to ownership, making them less suitable for this scenario.