In the Estate of Pinkham v. Cargill, Inc., case, the main issue was: a. whether Pipkham needed to prove if the injury, in fact, was caused by a piece of bone. b. whether Cargill made an express warranty by the mere sale of the sandwich. c. whether Pinkham would reasonably expect pieces of bone in a turkey sandwich according to the reasonable expectation test. d. whether Cargill made an implied warranty of fitness for a particular purpose by selling Pinkham the sandwich