A company is building an LLM-based question-answering chatbot to reduce the number of steps call center staff must take to answer customer inquiries. Which business metric should be used to evaluate the chatbot's impact?

Average call duration is the most direct and relevant business metric for evaluating an LLM-based question-answering chatbot designed to assist call center staff. If the chatbot successfully provides quick and accurate answers, staff will resolve customer inquiries faster, leading to a reduction in the average time spent on each call. This directly measures the chatbot's efficiency and its impact on operational costs and customer service speed. Website engagement rate is irrelevant as the chatbot's primary function is internal support for call center staff, not customer-facing website interaction. Corporate social responsibility and regulatory compliance are important business considerations but are not direct metrics for the operational efficiency or effectiveness of a question-answering chatbot in this context.