interesting(दिलचस्प) : arousing curiosity or interest; holding or catching the attention.
humorous(हास्यपूर्ण) : causing laughter and amusement; comic and having or showing a sense of humour.
platitude(साधारण बात) : a remark or statement, especially one with a moral content, that has been used too often to be interesting or thoughtful.
vigorous(जोरदार) : characterized by or involving physical strength, effort, or energy.
Hence best answer should be platitude(synonym- nullity ). option c is correct.