In the following questions, a word has been given in bold. It is then followed by three sentences in which the word has been used in either similar or different ways. Find the sentence/s in which the given word has been correctly used. If all the sentences are correct, choose option E as your answer. OBDURATE
I. Environmental campaigners loudly protested, "Abandon your obdurate refusal to reduce industrial emissions before ecological damage becomes irreversible!"
II. Had the management not remained obdurate during union negotiations, the prolonged labor strike could have been resolved peacefully.
III. Historical records indicate that the ancient fortress was built with obdurate stone walls capable of withstanding heavy artillery attacks.