Final answer:
Angry customers may primarily feel a loss of control, which is compounded by unclear information regarding a purchase or past unsatisfactory experiences, potentially leading to a perception of financial loss.
Step-by-step explanation:
The most important reason angry customers behave the way they do could be attributed to a combination of factors. However, if compelled to choose the most significant single factor, it is likely c) they felt a loss of control. When customers feel a loss of control over their situation due to imperfect or unclear information regarding a product or service, or from past experiences with purchases that did not meet their satisfaction, they may exhibit anger or frustration. Such emotions can be exacerbated if there's the perception of potential financial loss, which too can result in feelings of lost control. Each factor plays a part, but the profound emotional response tends to stem from a disrupted sense of autonomy and expectation.