Explanation:

- When a subscription is received in advance, it is money collected for services not yet rendered.

- Option 1: An income - This would be incorrect because the income is not yet earned until the service is provided.

- Option 2: An asset - This is not right either because an asset is something the company owns, and liability refers to something the company owes.

- Option 3: A liability - This is correct. Such prepayments create an obligation for the company to provide goods or services in the future. It is unearned revenue as the service is yet to be delivered.

- Option 4: None of the above - This is incorrect as there is an applicable option.