In each of the following questions, a word has been used in three different sentences. Choose the option corresponding to the sentence(s) in which the usage of the word is grammatically and contextually correct. REBUFF ​I. The tech startup’s ambitious acquisition proposal faced a swift and unceremonious rebuff from the board of directors, who valued their company's independence far too highly.
II. To rebuff the sudden onslaught of high-frequency cybersecurity attacks, the engineering team quickly deployed a multi-layered cryptographic firewall.
III. The seasoned diplomat managed to gracefully rebuff the hostile allegations made by the foreign media outlet without escalating international tensions.