Which Person with Parkinson's Disease Is Most Likely to Develop

Which person with Parkinson's disease is most likely to develop dementia?

A) Karen, who has mild cognitive impairment and whose posture is still excellent.
B) Emily, who has no cognitive impairment and is relatively old.
C) Shantal, who has visual hallucinations and whose gait has been severely affected by the disease.
D) Sara, who has no hallucinations, but a severe problem with her gait due to the disease.