Which service is used for voice communication in emergency situations?

The correct choice is the voice relay service, as this service is specifically designed to facilitate voice communication in emergency situations. During emergencies, rapid and clear communication is critical, and voice relay services allow individuals, especially those with hearing or speech disabilities, to connect with emergency responders through specialized operators who relay information back and forth.

In such urgent scenarios, the ability to communicate verbally can significantly impact response times and the effectiveness of emergency services. While text message services and video call services can also be useful, these options do not inherently prioritize immediate voice communication essential during emergencies. Additionally, restricted access services are typically meant for controlled access to information rather than direct communication, further differentiating them from the focus of voice relay services in urgent situations.