The correct answer is D. Agreement to sell is deemed to be sale.
Section 4 of the Sale of Goods Act, 1930 defines a sale as follows:
“A contract of sale of goods is a contract whereby the seller transfers or agrees to transfer the property in goods to the buyer for a price.”
Therefore, an agreement to sell becomes a sale when the seller transfers or agrees to transfer the property in goods to the buyer.
Option A is incorrect because it states that an agreement to sell becomes a sale when the seller transfers the property in goods. However, an agreement to sell can become a sale even if the seller does not transfer the property in goods. For example, if the seller agrees to sell goods to the buyer and the buyer agrees to pay for the goods, but the seller does not actually deliver the goods to the buyer, the agreement to sell is still a sale.
Option B is incorrect because it states that an agreement to sell becomes a sale when the seller agrees to transfer the property in goods. However, as explained above, an agreement to sell can become a sale even if the seller does not agree to transfer the property in goods.
Option C is incorrect because it states that an agreement to sell becomes a sale when the time elapses or the conditions subject to which the property in the goods is to be transferred are fulfilled. However, the time elapsing or the conditions subject to which the property in the goods is to be transferred are not essential for an agreement to sell to become a sale. For example, if the seller agrees to sell goods to the buyer and the buyer agrees to pay for the goods, the agreement to sell is a sale even if the time for delivery of the goods has not yet elapsed or the conditions for delivery of the goods have not yet been fulfilled.
Therefore, the correct answer is D. Agreement to sell is deemed to be sale.