Final answer:
The most advantageous option for a seller who sells a parcel of real property using a conditional sales contract instead of a grant deed and carrying back a first trust deed is for the seller to retain legal ownership of the property until the buyer makes the final payment.
Step-by-step explanation:
The most advantageous option for a seller who sells a parcel of real property using a conditional sales contract instead of a grant deed and carrying back a first trust deed would be option C) The seller retains legal ownership of the property until the buyer makes the final payment.
This method provides the seller with more security and control over the property, as they retain legal ownership until the buyer fulfills the terms of the contract. This ensures that the seller will receive the full payment before transferring the legal ownership to the buyer.