{
    "meta_info": {
        "case_id": "Q10",
        "bench_subset": "NeuroBench-Core",
        "difficult": 1.0,
        "original_dataset": "Core_QA",
        "references": "R9"
    },
    "agent_input": {
        "data_path": "",
        "instruction": "This is a standalone EEG/BCI knowledge multiple-choice question. No EEG data file is needed. Please answer by selecting exactly one option: A, B, C, or D.\n\nQuestion: What is one core distinction between ERP and ERD/ERS analyses?\nA. ERP can only be used in sleep, whereas ERD/ERS can only be used in epilepsy.\nB. ERP is a frequency-domain index, whereas ERD/ERS is a purely time-domain voltage index.\nC. ERP usually emphasizes event-locked voltage changes, whereas ERD/ERS emphasizes decreases or increases in power within specific frequency bands.\nD. ERD/ERS is unrelated to oscillatory power and only reflects impedance changes."
    },
    "eval_config": {
        "parser_prompt": "### ROLE\nYou are a precise JSON Extraction Engine for multiple-choice EEG/BCI QA responses. Your sole task is to extract the final selected answer option.\n\n### TASK\nExtract the final selected option from the agent report.\n\n### STRICT CONSTRAINTS (MANDATORY)\n1. Output ONLY a valid JSON object.\n2. DO NOT include Markdown code blocks.\n3. DO NOT include any conversational text, explanations, or units.\n4. The key must be EXACTLY \"selected_option\".\n5. The value must be one of \"A\", \"B\", \"C\", \"D\", or null.\n6. If multiple options are mentioned, extract only the final answer option.\n7. If the selected option is missing or unclear, return {\"selected_option\": null}.\n\n### OUTPUT TEMPLATE\n{\"selected_option\": <string|null>}",
        "metrics": [
            {
                "metric_id": "qa_option_accuracy",
                "type": "categorical_check",
                "target_key": "selected_option",
                "weight": 100,
                "params": {
                    "gt_value": "C"
                }
            }
        ]
    }
}