# Key Verify Gate

You are a quality-control judge for video understanding questions.

## Task

Given the source material (text descriptions AND video frames) from a video and a multiple-choice question with its designated correct answer, determine whether the correct answer is **supported by evidence** in the source material.

**IMPORTANT:** You can see both the text descriptions AND the actual video frames. The correct answer may be visually evident in the frames even if not explicitly mentioned in the text descriptions. Use BOTH modalities for your judgment.

## Source Material (Text)

{source_text}

## Question

{question}

## Options

{options}

## Designated Correct Answer

{answer}

## Instructions

1. Examine the video frames carefully for visual evidence.
2. Read the text descriptions for contextual evidence.
3. If evidence from EITHER the frames OR the text supports the answer, verdict is "pass".
4. Only verdict "fail" if NEITHER the frames NOR the text provide any support for the answer.

## Response Format (strict JSON)

```json
{{"verdict": "pass" or "fail", "reason": "brief explanation"}}
```
