Here's a breakdown:
* Gracias: Thank you
* porque: because
* me gustan: I like them
Therefore, the correct translation is "Thank you because I like them".
It's important to note that "les" is used when referring to multiple people in the informal "ustedes" form. However, "gustar" is a verb that requires the use of the personal pronoun "me" (I), "te" (you), "le" (he/she/you), etc.
This phrase implies that the speaker is expressing gratitude for something they like. The context would determine what "them" refers to. For example:
* "Gracias porque me gustan tus flores." (Thank you because I like your flowers.)
* "Gracias porque me gustan tus amigos." (Thank you because I like your friends.)
Remember to use the correct personal pronoun when using "gustar" in Spanish.