Afeed store owner agreed to purchase several tons of grain products at a specified price from a large supplier of cattle feeds. the supplier later failed to deliver the promised grains, and the owner was forced to cover by purchasing from local producers at a higher price. the owner contacted a large law firm in the city and obtained their agreement to represent him in connection with his possible claims against the supplier. due to error, the applicable statute of limitations period passed without the filing of any action on the owner's behalf. the owner retained another lawyer and sued the large law firm for malpractice. the jurisdiction retains traditional contributory negligence. in addition to the firm's negligence, what else does the owner have to establish as part of his prima facie case? a he had a good faith claim against the supplier that was lost by the law firm's dilatoriness. b he would have recovered from the supplier if an action had been timely filed. c he did not contribute to the failure to timely file an action through his own negligence. d the losses resulting from breach of the sales agreement by the supplier severely harmed his financial situation.