You are designing an agent that processes vendor invoices.

Option D applies the correct hybrid pattern. Anthropic distinguishes workflows—where LLMs and tools execute along predefined code paths—from agents, where the model dynamically determines how to proceed. Anthropic recommends choosing the simplest architecture that meets the requirement: workflows provide predictability and consistency for well-understood tasks, while agents are valuable where flexible model-driven decisions are necessary.

Standard invoice processing is explicitly described as a small number of known steps. That makes a deterministic workflow the appropriate default because the path can be tested, monitored, and reproduced. The unexpected-format branch is different: the system must reason among rerouting, requesting clarification, or human escalation. That decision point is where agentic flexibility adds value.

A makes the entire process autonomous even though most steps do not require autonomy, increasing cost, latency, and unpredictability. B introduces multiple specialized agents despite no demonstrated need for that complexity. C collapses deterministic processing and exception handling into one monolithic model call, making validation and debugging harder.

Therefore, D combines workflow predictability with targeted agentic reasoning. Relevant Study Guide topics: workflows versus agents, routing, exception handling, hybrid agentic architecture, escalation, and complexity minimization.

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