Explanation:

- Legacies are typically treated as amounts received by an organization, often as part of a will or testament.

- They are not considered a regular income but a one-time event, hence usually not a liability or a revenue receipt.

- Option 1: Liability - Legacies are not liabilities. Liabilities are obligations an organization must settle in the future.

- Option 2: A Revenue Receipt - Revenue receipts refer to day-to-day income which legacies are not.

- Option 3: A Capital Receipt - This is correct as legacies are more likely to be treated as capital receipts due to their nature of being non-recurring and long-term.

- Option 4: None of these - Not applicable as option 3 is correct.