{
    "meta_info": {
        "case_id": "Q24",
        "bench_subset": "NeuroBench-Core",
        "difficult": 1.0,
        "original_dataset": "Core_QA",
        "references": "R17"
    },
    "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: When a phase reversal appears in a bipolar montage, what is a reasonable interpretation?\nA. The location must have the lowest electrode impedance.\nB. A local potential maximum or minimum may lie near the shared electrode between adjacent derivations.\nC. The activity is necessarily non-neural.\nD. The activity can only be seen after recomputing the data with average reference."
    },
    "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": "B"
                }
            }
        ]
    }
}