Research Would Predict That _____ Would Show the Largest Intellectual

Research would predict that _____ would show the largest intellectual declines in the coming years.

A) 68-year-old Jay,who is married and leading an active social life,
B) 69-year-old Grace,who lives alone and is socially inactive,
C) 70-year-old Pedro,who is married but socially inactive,
D) 71-year-old Alana,who is lives alone but is socially active,