38. What can be inferred from the passage? (A) The more dopamine we have, the more likely we will suffer from Parkinson’s disease. (B) Not everyone has the autoreceptors which control the amount of dopamine. (C) The dopamine system is crucial to propelling humans to take challenges. (D) Those who love dangerous tasks often struggle with apathy. (E) Risk-taking is not related to the nerve cells in the brain.