Here are some ways to answer:
Formal:
* Je m'appelle [your name]. (This is the most common and polite way to respond)
Informal:
* On m'appelle [your name]. (This means "I am called [your name]" and is more casual)
* [Your name]. (You can simply state your name if you are speaking to someone you know well)
Examples:
* Question: Comment t'appelles-tu?
* Answer (formal): Je m'appelle Marie.
* Answer (informal): On m'appelle Pierre.
* Answer (casual): Pierre.
Remember, the level of formality you use will depend on the context and your relationship with the person asking the question.