(a) That's wrong. You might think that this is a clear case in which damages would not provide an adequate remedy, therefore justifying an order of specific performance. After all, B says a replacement designer of the same calibre is not available, even at greater cost.

But this is a special type of contract. It is a contract involving the performance of personal services, and the courts have made it very clear that they will not order specific performance of such agreements. The reason is that personal services depend on the goodwill of the performer, and if performance were ordered, it might be carried out badly, leading to further disputes.

An example is the case of Lumley v Wagner (1852) 42 ER 687.  Wagner, a singer, had contracted to sing in a certain number of performances in Lumley’s theatre.  In considering another issue, the court observed that it would not have ordered specific performance of this promise (a promise for personal services) because it would have involved too much supervision by the court and interfered too much with Wagner’s personal liberty.

It is most likely that in the example, an order of specific performance would be refused, and damages would be awarded instead.