Which of the following is not essential for the transfer of title in goods from the seller to the buyer?

Under section 20 of the Sale of Goods Act, property in specific goods in a deliverable state passes when the contract is made, even if payment or delivery is postponed, so "Physical Delivery of the goods" is not essential. Property cannot pass in unascertained goods (section 18), and it passes only when the parties intend it to (section 19), so "Ascertainment of the goods" and "Intention of the parties that the property should pass" are both essential.