The best answer here is d, the buyer may use the remedies in a and c.
If the DVD player is defective, the buyer may submit it for repair. [CC §1793.2(b)–(c).] If the service center cannot repair the player after a reasonable number of attempts, the buyer must receive a replacement or refund, at the buyer’s option, in most cases within 30 days. [CC §1793.2(b), (d).]