The following table shows the symptoms in four patients. Each patient suffers from a different disease.

Patient Disease Cause Symptom
A Tuberculosis Bacteria Difficulty breathing, coughing
B Polio Virus Paralysis
C Food poisoning Bacteria Vomiting, diarrhea
D Huntington's disease Hereditary Physical movement beyond patient's control
Which patient's musculoskeletal system is affected by an infectious agent?

Select one:
a. A
b. B
c. C
d. D