Aging refers to a continuous and irreversible process that begins or accelerates the body after sexual maturity;. According to the definition above, which of the following options is aging? ["Elderly people's height has dropped, their spine is bent, their skin is loose, and their hair must fall off.", 'er a cadre retires, he sleeps badly, is emotionally upset, and is unwilling to associate with others.', 'oung man was originally lively and enthusiastic, but was unhappy because of his heavy schooling.', "orker's hearing loss due to working in a noisy environment for a long time."]