Question: What is Occitan a branch of?
Sentence: Differentiation has arisen generally because Spanish, Asturian, and Galician-Portuguese share certain peripheral archaisms (Spanish hervir, Asturian/Portuguese ferver vs. Catalan bullir, Occitan bolir "to boil") and innovatory regionalisms (Sp novillo, Ast nuviellu vs. Cat torell, Oc taurèl "bullock"), while Catalan has a shared history with the Western Romance innovative core, especially Occitan.
Answer in sentence: yes