Question: When constructing a MAP-DeleteSubscriberData Ack message from a DSA command, how should the IWF populate the `regionalSubscriptionResponse` in `DeleteSubscriberDataRes` if it receives a `Network-Node-Area-Restricted` indication within the DSA-Flags AVP?
Option 1: Set `regionalSubscriptionResponse` to `networkNode-AreaRestricted`
Option 2: Set `regionalSubscriptionResponse` to `regionalSubscNotSupported`
Option 3: Leave `regionalSubscriptionResponse` absent in the response
Option 4: Set `regionalSubscriptionResponse` to a generic error code
Explanation: According to the specified mapping rules for DSA to DeleteSubscriberDataRes/Error, if a Network-Node-Area-Restricted indication is received within the DSA-Flags AVP, the IWF should specifically set `regionalSubscriptionResponse` in `DeleteSubscriberDataRes` to `networkNode-AreaRestricted`. This ensures accurate translation of restrictions between the Diameter and MAP protocols.