Hybrid calling refers to integrating on-prem calling with cloud services.

• A. Involves only cloud-based calling
• B. Uses on-premises hardware exclusively
• C. Requires a VPN connection to the cloud
• D. Integrates on-prem calling with cloud services

Answer: (D)

Hybrid calling means blending on-premises calling infrastructure with cloud services, so users can place and receive calls across both environments and take advantage of features from the cloud while keeping on-prem systems.

The choice that describes integrating on-prem calling with cloud services matches this idea exactly. It captures the essence of hybrid by pointing to a combined setup rather than a cloud-only or an on-prem-only approach. The other statements describe scenarios that are exclusively cloud-based, exclusively on-premises, or insist on a VPN, which is not what defines hybrid calling.