Hi!
Yes I do mean commercial law but I don't think it has to be specific to just this and they will probably ask me why I want to pursue a career in law just generally.
And yes I am asking in reference to an interview question- sorry I forgot to write this.
Actually, if interviewers ask this question, they will almost always ask about your motivation for commercial law rather than just law (precisely because they do not want generic reasons).
Sometimes, law firms will ask both questions. In which case, your answers are a fine starting point for "why law?", but you would need to expand on your answers and back up your reasons with some evidence. For example, it's fine to say you are pursuing a career in law because you want to help people, but as Jai suggests, consider how this justifies your interest in law over other professions.
If you wanted to answer the question: "Why commercial law?", you should tailor your answers to
commercial law and not just law generally.