Emphatic stress is the placement of greater stress on a particular word or phrase in a sentence or utterance. For questions on emphatic stress, the rule is to select the option that has a word that contradicts the emphasised word/ word in capital letters. In this case, the answer is option D. because it has "employers" instead of "employees". This makes sense because the sentence is the appropriate response to the question as it clarifies a misapprehension in the question: