I think a. use of verb tenses
"think"
B- casual, relaxed, and indifferent to what others think of him.
The answer: Brain
In Angie's situation, she has her spinal cord intact but still has difficulty walking. Medically, balance, gait and walking require complete functions of the brain and spinal cord. Should her spinal cord and its nerves be intact, the problem lies with the other important factor which is the brain. The brain sends the signals to do any activity.