How Was Matthew S

How was Matthew S. able to survive with only half a brain?

A) his brain was already wired to function with only one hemisphere, but was previously inhibited from doing so"
B) Matthew S. was able to survive, but because his brain was far past the sensitive period, he was unable to function normally"
C) his brain rewired itself to take over missing functions, and redrew maps on a larger piece of tissue"
D) his brain rewired itself to take over the missing functions, and redrew maps on a smaller piece of tissue"