Concept:A contract is discharged when the parties fulfill their obligations, but failing to deliver to the correct person is a breach.
Explanation:The motor dealer agreed to sell the car specifically to Mr X.
Instead of delivering the car to Mr X, he delivered it to Mr Y on the agreed date.
Delivering to the wrong party means the dealer failed to perform his contractual duty toward Mr X.
This failure to fulfill a contractual obligation is known as a breach of contract.
It is not performance because the correct delivery was not made to Mr X.
It is not frustration because no unforeseen event prevented the delivery.
It is not an agreement because Mr X did not consent to delivery to Mr Y.
Answer:D. breach