Which of these individuals probably has the highest chance of developing a stress-related illness? Dave, who lives in a bachelor pad with a fraternity brother, and works at a Fortune 500 company Layla, who lives with two close friends she has known since elementary school, and does not work because she is independently wealthy Pam, who lives by herself, and volunteers at a homeless shelter every weekend Xu, who lives by himself, works at home, and prefers to keep to himself