Which of the following is an example of an external factor causing stress?

An external factor causing stress is something that originates from outside the individual rather than stemming from their internal thoughts, feelings, or biological makeup. A sudden illness directly impacts an individual’s life circumstances by introducing unexpected challenges and uncertainties, which can create a significant source of stress. This is an example of an external factor because it is an event or situation that affects a person's well-being and is beyond their control.

In contrast, the genetic predisposition relates to inherent traits that can influence stress responses but are not directly caused by external events. A positive work environment is generally a stress-relieving factor rather than a source of stress, thus making it less relevant in this context. Lastly, personal ambitions, while they can lead to stress, stem from internal motivations and desires rather than external conditions. Therefore, the sudden illness accurately exemplifies an external stressor, as it reflects an uncontrollable situation that can have profound effects on one's mental and emotional health.