【单选题】

Questions 24—26 are based on the passage about human intelligence. You now have 15 seconds to read Questions 24—26. The best statement of the main idea of the passage is that ______.A．human brains differ considerably

B．the brain a person is born with is important in determining his intelligence
C．environment is crucial in determining a person’s intelligence
D．persons having identical brains will have roughly the same intelligence