Explanation:

- An agreement to sell becomes a sale in Option:1, Future date, when the conditions of the agreement are fulfilled, and the ownership of goods is transferred.

- Option:2, immediate effect, does not apply because an agreement to sell implies a future event or condition. A sale occurs immediately if the contract stipulates immediate transfer, not under an agreement to sell.

- Option:3, 30 days, is specific and only applicable if the agreement explicitly states this duration. Typically, this is not a general rule for transforming an agreement to a sale.

- Option:4, None of the above, isn't applicable here as future fulfillment turns an agreement to a sale, making Option 1 correct.

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