Finish this sentence: The four elements a plaintiff must establish to prove a defendant was negligent are $(1)$ the defendant owed a duty to the plaintiff to conform to a certain standard of conduct in order to protect the plaintiff against unreasonable risk of harm, $(2)$ the defendant did not conform to the standard required, $(3)$ a reasonably close causal connection existed between the conduct of the defendant and the injury to the plaintiff, and $(4)$