A is correct: DTMF fallback provides a reliable alternative when speech recognition fails or confidence scores are below threshold, improving caller experience and reducing errors.
B is incorrect: Training only on scripted data limits the NLU model's ability to understand natural language variations, reducing recognition accuracy in real-world conversations.
C is correct: Customizing the speech recognition engine with domain-specific terms enhances recognition accuracy, especially for industry jargon and product names.
D is incorrect: Static menus restrict natural language interaction and do not leverage AI capabilities, limiting flexibility and caller satisfaction.
E is correct: Confidence thresholds allow the system to manage uncertain inputs gracefully, prompting users for clarification or fallback to DTMF input to improve routing accuracy.
F is incorrect: Disabling speech recognition reduces system intelligence and caller convenience; proper scaling and resource management should handle high volumes without disabling features.