Task completion rate is the strongest answer because the company ' s stated business objective is not merely to generate responses quickly; it is to maximize the number of customer queries that are successfully resolved . AWS explicitly includes “task completion rate, user satisfaction, cost per interaction” as business-objective alignment metrics for AI applications.
Task completion rate measures whether an AI assistant actually accomplishes the user ' s intended objective. For a customer-service assistant, successful completion could mean resolving an account question, completing a requested action, supplying the correct information, or otherwise finishing the customer interaction without unnecessary escalation.
Model inference latency, option D, is an important operational metric, but it measures something different. AWS defines inference latency as the time between requesting a model prediction and receiving the result. AWS ' s Generative AI Lens separately identifies latency and throughput as performance characteristics. Lower latency can improve responsiveness and potentially enable greater processing capacity, but a very fast response that fails to resolve the customer ' s problem does not satisfy the stated objective.
User satisfaction score measures perceived experience rather than directly measuring successful query resolution. Cost per interaction measures economic efficiency and is useful when optimizing operational cost, but again it does not indicate whether the query was resolved.
If the question had explicitly asked for a pure infrastructure-capacity metric such as the maximum number of requests processed per unit of time, throughput would be the most direct measure. Throughput, however, is not provided as an option. The wording specifically uses “queries resolved,” which makes successful task completion the principal business outcome.
Therefore, among the available choices, A. Task completion rate most directly validates whether the AI assistant is achieving the required business objective.