Unless otherwise agreed, the Sale of Goods Act provides that title to goods passes from seller to the buyer for the sale of unascertained goods or future goods by description:

a$.$

When the buyer retains the good beyond a reasonable time.

b$.$

A & B

c$.$

When the buyer received notice that it has been done.

d$.$

When goods of that description and in a deliverable state are appropriated to the contract by one party with the assent of the other.