iCloud Security Questions
You can actually enter any information as your answers. Moreover, this is better option actually as it adds security against people who may know or guess your answers.
The only important thing is to remember this information or at least keep it safely. You'll need it in case of any problems with access to your iCloud account either to restore by yourself or through tech support.
Your options are:
1. Memorize your answers
2. Write them down (not safe!)
3. Use any password utility (like 1password, for instance) that help you keep all your info safe.
That's the easiest way to deal with the subject. Changing questions requires you to communicate with Apple with no guarantees of success.
Hope this helps.