【单选题】

Last year, Sean Martinovich, from Whitianga, had life-saving surgery when a golf-sized tumor was removed from his brain stem.But the operation left half his face paralyseD、He talked with a slur, sometimes dribbled out of the side of his mouth and coulD、not close his eye properly.Although he could run around with the other boys in the playground, when they laughed he could not laugh with them. Without a smile, he would suffer psychologically and emotionally.

Last week, 6-year-old Sean had seven hours of microsurgery that should give him back his smile.DoctorBartlett removed a nerve from the back of one of Sean’s legs and transplanted it into his face, On the normal side of his face the nerve divides into lots of little branches. "We’ll cut those nerve branches and then we’ll take a nerve graft from one leg and tunnel it across his face from one side to the other end join that on to the nerve that’s been cut on the good side of his face,"DoctorBartlett said, before the operation. "If this was not fixed, he could face physical and emotional problems as he got older,"DoctorBartlett saiD、"Socially, people can become quite withdrawn because of face paralysis. It’s easy for people, especially children, to become rather emotionless because they prefer the flatness of no movement on either side to the weirdness of an asymmetry of smiling off one side and having this twisted face."
Sean is not smiling yet. Over the next six months the nerves will grow across the face to the damaged side and after that movement will hopefully come back. Sean’s parents, Steve and Wendy Martinovich, said they had been through a year of hell.But their son was a determined boy who just got on with it, said Mrs. Marfinovich. They are amazed at the technology that they hope will restore the cheeky smile they love so much. ForDoctorBartlett the microsurgery is almost routine. For Sean’s parents, it is a miracle.
How old was Sean Martinovich when the golf-sized tumor was removed from his brain stem
A、4 years olD、
B．5 years olD、
C．6 years olD、
D．7 years olD、