Question: In a Telecommunication Management context, using the Generic Network Resource Model (NRM), what happens to candidate notifications when the `notificationFilter` attribute is absent in a `NtfSubscriptionControl` instance?
Option 1: They are discarded and not sent to the notification recipient.
Option 2: All candidate notifications are sent to the notificationRecipientAddress without filtering.
Option 3: The system applies a default filter, reducing the number of notifications sent.
Option 4: The subscription creation fails due to missing filter criteria.
Explanation: If the `notificationFilter` attribute is absent in a `NtfSubscriptionControl` instance, all candidate notifications are sent to the notificationRecipientAddress. This indicates that without an explicit filter, no filtering is applied, and all notifications of the specified types (or all types if not specified) are forwarded to the recipient.