Tonya Has Been Diagnosed as Having Parkinson's Disease and Her

Tonya has been diagnosed as having Parkinson's disease and her friend, Ruth, has been diagnosed with major depressive disorder. Tonya and Ruth received their diagnoses three years ago. One of their mutual friends, Sarah, has had a chronic alcohol problem for ten years. Which of the following statements is true regarding their likelihood of developing delirium?

A) Sarah, Tonya and Ruth are equally likely to develop delirium
B) Tonya is more likely to develop delirium than Ruth, and Sarah is less likely to develop delirium than Tonya and Ruth
C) Ruth is more likely than Sarah to develop delirium, and Tonya is more likely than Sarah to develop delirium
D) Sarah is more likely to develop delirium than Tonya and Ruth, and Tonya is more likely to develop delirium than Ruth