Mack is injured by a tractor manufactured by westco. in order to defend against a negligence claim based upon the product, westco may show that it exercised due care by all of the following except:
a. inspecting and testing any purchased components used in the final product.
b. showing the absence of privity of contract between it and the consumer.
c. using the appropriate production process.
d. placing adequate warnings on the label to inform the user of dangers to which an ordinary person might not be aware.