Dangerous as anger can be, it is also natural, even necessary, and has been hard-wired into the brain by evolution. Most obviously, anger helped people survive. As soon as this survival was threatened, anger was triggered, along with violent defensive action. More surprisingly, perhaps, anger also helped early humans to live together in groups, acting as a kind of warning signal in the form of threatening facial expressions, clenched fists, reddening cheeks, and so on. This let others know that their behavior was unacceptable, that they were invading someone’s personal space and that they risked physical retaliation. At first glance, anger seems relatively simple. Ask the man in the street to define it and he will probably say ‘it’s what happens when people annoy you.’ But anger can take many forms and has numerous different triggers. And what infuriates one person may pass by another unnoticed. One individual can make her way through a bustling crowd, or sit next to a screaming child, and seem perfectly relaxed. But if someone questions her political beliefs, or disrupts her plans, she will fly into an uncontrollable rage. For some, anger is triggered more by petty annoyances than by major catastrophes. They will be calm and methodical during a bereavement, for example, or when travelling to the hospital for an operation, but as soon as the neighbor’s car alarm goes off, or the printer runs out of ink, they explode. For others, it is threats to their money, property, status or time that act as the major catalyst. They may let the petty irritations go, but if their car is scratched or their authority questioned, they become enraged. Finally, some will laugh off both petty irritations and threats to their money or status. For them, rule-breaking is the most infuriating thing. This is especially true of those with obsessive compulsive or autistic traits: people who like and need things to be regular and ordered. And such rules can be more like vague, unspoken agreements. For example, someone may be sensitive about their acne or low income. Friends understand this and so the subject is never raised. One evening, someone makes a harmless remark and is shocked to see their friend explode with rage. But it wasn’t the fact that his low income or bad skin had been mentioned, nor even that he felt humiliated; his anger was sparked because someone had broken the rules. From the passage it can be summed up that… A. For an obsessive-compulsive person or someone with autistic traits, he/she can get angry when someone has broken the rules by, for example messing up the order or regulation and not doing what they are asked to do. B. Some people get angry for small things, while some get angry for more serious matters. C. Most people get angry with something they cannot control or predict, or something they are very sensitive to. D. Amongst many conditions that make people angry, the most frequent reason is when people raise a topic that relates to the person’s bad experience in the past. E. Some people get angry for small or serious things and some others might get angry not due to small or serious matters, but because people ask them what they do not like to be asked