If you set the Read/Write failover policy as Automatic, in the event of a datacenter or Azure regional outage, the databases will failover automatically.
For Automatic failover, you can also set the Read/Write grace period as shown below.

Option B is incorrect because this is based on a dataceter or Azure regional outage Option C is incorrect since the policy is set as Automatic, so the databases can't be failed over manually.
https://docs.microsoft.com/en-us/azure/azure-sql/database/auto-failover-group-overview?tabs=azure-powershell