Each "SIP Trunk Channels" license supports 1 simultaneous call (Option A). Multiple licenses are required to increase capacity (e.g., 10 licenses for 10 calls). Options B, C, and D incorrectly suggest a single license supports multiple calls.References: Avaya IP Office SIP Trunk Configuration Guide.

Mobile Twinning (Option B) allows a user to link their IP Office extension to an external number (e.g., a mobile phone), so calls ring both devices simultaneously or sequentially. This is distinct from Option A (Call Forwarding), which redirects calls to another internal extension or voicemail, not typically an external number without additional setup. Option C (Remote Call Forward) is not a standard IP Office term, and Option D (Call Diversion) is a synonym for forwarding but less specific to external numbers.References: Avaya IP Office Mobile Twinning Configuration Guide.

The "Voicemail Pro" license (Option C) enables the Contact Recorder feature within Voicemail Pro for call recording. Options A and B are user licenses, and Option D is a legacy edition not specific to recording.
References: Avaya IP Office Voicemail Pro Administration Guide.

Voicemail Pro, an advanced voicemail application for IP Office, includes a built-in backup and restore feature. Option D, "In Voicemail Pro Preference > General options > Backup & Restore," is correct because the Voicemail Pro client interface allows administrators to configure automatic backups under the
"Preferences" menu, specifically in the "Backup & Restore" section. Here,settings like backup frequency, location, and retention can be defined. Option A (Manager program) is incorrect as Manager handles system configuration backups, not Voicemail Pro specifically. Option B (automatic backup at midnight) is a partial truth but lacks specificity, as the timing is configurable in Voicemail Pro settings. Option C (PC backup method) is vague and not a standard feature of Voicemail Pro.References: Avaya IP Office Voicemail Pro Administration Guide.