Final answer:
A patient whose left arm is paralyzed but retains sensory and motor functions might be suffering from Conversion Disorder, which involves neurological symptoms without an identifiable medical cause for the paralysis (option C).
Step-by-step explanation:
A patient with an intact ability to sense and initiate movements in their left arm, but who cannot actually move it, might be suffering from Conversion Disorder. This condition involves neurological symptoms, such as paralysis, that are incompatible with any recognized medical or neurological condition. In this case, despite having the ability for sensory and motor functions, the patient is unable to move their arm, which indicates the absence of a structural or physiological neurological cause for the paralysis.
By contrast, Hemiplegia is a condition involving paralysis on one side of the body typically caused by brain damage from a stroke, accident, or another neurological condition. Hemiparesis is similar but refers to a weakness rather than complete paralysis. Cerebral palsy is a group of disorders that affect movement and muscle tone or posture caused by damage that occurs to the immature brain as it develops, most often before birth.
Hence, the answer is option C.