A patient visits a neurologist because they no longer have control of moving their right arm. They claim that they try to "tell" their arm to move, but it just doesn't respond to the command. Which of the following statements best describes a possible diagnosis to explain this patient's symptoms?

a. The sensory neurons of the central nervous system (CNS) are not functioning properly.
b. The motor neurons of the somatic nervous system (SNS) are not functioning properly.
c. The motor neurons of the autonomic nervous system (ANS) are not functioning properly.
d. The sensory neurons of the somatic nervous system (SNS) are not functioning properly.