Option (क) is the correct answer because the provided context mentions that the essay includes the names of great personalities like Buddhadev, Mahavir Swami, Nagarjuna, Shankaracharya, Kabir, and Nanak, who all contributed to society in their respective times. This clearly indicates that the need for social reforms has persisted across different eras, making the statement 'सुधारों की आवश्यकता हर युग में बनी रहती है' the most accurate. Options (ख) and (ग) are incorrect as reform is not limited to big thinkers or just the modern age, and option (घ) is logically flawed as defects do not completely cease to exist.