Ali, Bao, Cyle, and Dan all work in a high-pressure sales environment. They all have done relatively well in their jobs over the past couple years. However, this last quarter has been tough for the entire company. Based on the backgrounds described below, who of the sales force is MOST at risk for a stress-related illness?

A) Ali, who lives alone but has a number of acquaintances at the coffee shop.
B) Bao, who lives alone and just prefers to keep to himself.
C) Cyle, who lives with his girlfriend and is considered the "life of the party."
D) Dan, who lives alone but Skypes with his friends from back home.