Choose 1 option.

As documented in the AgentForce Prompt Template and BYOLLM (Bring-Your-Own-LLM) Deployment Guide, each prompt template references a specific LLM configuration by name and ID. When migrating components between environments (e.g., from sandbox to production), the referenced LLM must also exist in the target org with the exact same name and identifier.

If the LLM configuration is missing or named differently in production, the deployment fails, as the prompt template cannot resolve its model dependency.

Option A is incorrect because specifying a custom LLM type does not resolve the missing configuration issue. Option B is incorrect because BYOLLM is supported in production, provided it is correctly registered.

Therefore, the error occurs because the LLM name or configuration ID does not match between sandbox and production, making Option C the correct answer.