By the way a C in the language for which you want to be a translator is not good at all./|||Do you mean besides taking an actual translator/interpretor program?
I imagine if you are wanting to be a translator, you would want another language besides Spanish? Or are you looking for any subject that would be a nice background or accompany a translator career?
1. If you are wanting another language: I would try to choose a language that is used alot. Where are you planning to live (what is popular language there, besides Spanish?).
2. If you are looking for a non-language course (as in not learning a new language), then I would think a subject that studies languages would assist your career. These are my suggestions: English Language/Literature (yes courses for studying the history of the language, or just literature)........., Linguistics, Anthropology or some other courses in Social Sciences, where you learn about many cultures.