Option (d) is correct because the textbook explicitly mentions that India's 'economic emergence on the world stage' is a factor that justifies its claim to a permanent seat. Additionally, India being the 'world's largest democracy' indicates a stable political system, which strengthens its candidature. Option (a) is incorrect as the context shows nuclear capability is actually a concern for some countries. Option (b) is not mentioned as a specific weightage factor. Option (c) is weak because Asia already has representation through China, and the context emphasizes representation for Africa and South America instead.