Use only the attached synthetic input. Return a JSON object with these exact fields: A_mwh, B_mwh, incorrect_row, output_unit. Use null for information not stated. Preserve identifiers, units and revision states. Lists follow first appearance in the input, except an explicitly requested chronological order. Use snake_case for categorical labels. Do not add inferred engineering decisions.
Field types: {"A_mwh": "number", "B_mwh": "number", "incorrect_row": "string", "output_unit": "string"}

Task: Calculate the reference result with ordinary code or spreadsheet formulas. Use AI to locate and explain discrepancies, not as the sole arithmetic authority.
Apply the kWh-to-MWh conversion exactly once.
Flag row B without changing its source inputs.
Keep the output unit with the result.