Explanation:

- Could:

- Used to express a polite request.

- Less formal than "may" but still very polite.

- Example: Could you pass the salt?

- Dare:

- Not typically used for polite requests.

- Often implies a challenge or courage.

- Example: Dare I ask why you're late?

- May:

- Used for formal requests or asking for permission.

- More formal than "could."

- Example: May I leave the room?

- Shall:

- Often used to offer help or make suggestions.

- Less common in modern requests.

- Example: Shall we dance?

In the context of asking for help, "could" fits best.

Option 2: Could is the most suitable word.

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