Lefties are at higher risk of ______.

A．The right hand is controlled by the left side of the brain, and the left hand is controlled by the right side of the brain.
B．Right-handers' speech-language center is in brain' s left-hemisphere, while left-handers' speech-language center is in brain's right-hemisphere.
C．The development of right and left side of brain is interactive.
D．The human central nervous system is just like a circuit.

A．a private servant
B．someone who does things privately
C．soldier
D．the automated machine which can offer change for a dollar