On the Caribbean island of Guadeloupe, a researcher examined 35 patients with atypical Parkinson' s disease and compared their eating habits to those of 65 healthy adults. She found that all of the patients with atypical Parkinson' s regularly ate the tropical fruits soursop, custard apple, and pomme cannelle, whereas only 10 of the healthy adults regularly ate these fruits. From this, she concluded that eating these fruits causes atypical Parkinson' s. Which one of the following, if true, most strengthens the researcher's reasoning?
A: The 10 healthy adults who regularly ate soursop, custard apple, and pomme cannelle ate significantly greater quantities of these fruits, on average, than did the 35 atypical Parkinson's patients.
B: Of the healthy adults who did not regularly eat soursop, custard apple, and pomme cannelle, most had eaten each of these fruits on at least one occasion.
C: In areas other than Guadeloupe, many people who have never eaten soursop, custard apple, and pomme cannelle have contracted atypical Parkinson's.
D: For many of the atypical Parkinson's patients, their symptoms stopped getting worse, and in some cases actually abated, when they stopped eating soursop, custard apple, and pomme cannelle.
Choose A, B, C or D as your solution.
D