Explanation
In a Public Read Only sharing model, all users can view cases in a Queue is the correct statement that describes the difference between a Private and Public Read Only organization-wide default sharing model on cases. Organization-wide default sharing model is a setting that determines the baseline level of access users have to each other's records. Private sharing model means that only the record owner and users above them in the role hierarchy can view and edit records, unless access is granted by other means, such as sharing rules or manual sharing. Public Read Only sharing model means that all users can view records, but only the record owner and users above them in the role hierarchy can edit records, unless access is granted by other means.
Queues are locations where records are routed to await processing by a group of users. Queues can be used to assign cases to the users who have the appropriate skills, availability, or capacity to work on them. Users who are members of a queue can view and take ownership of records in that queue. Users who are not members of a queue can view records in that queue if the organization-wide default sharing model is Public Read Only or higher, but they cannot take ownership of those records. Verified References: :
https://help.salesforce.com/s/articleView?id=sf.sharing_model_fields.htm&type=5 :
https://help.salesforce.com/s/articleView?id=sf.customize_queues.htm&type=5 :
https://help.salesforce.com/s/articleView?id=sf.customize_casequeues.htm&type=5