Most often this question is answered after the interviewer's case introduction/ description when asking you "what would be your e.g. first step to approach this" or "which questions should be answered before thinking about how to solve this case". This seems to be an interviewer-led case, because she/he starts with one question as a first step and you can expect that the next question will follow after your answer. The interviewer expects precise and focused answers to each question asked.
Your answer can end with "... This step could be followed by action xy", but you shouldn't start to explain "action xy" before asking e.g. "would you like to hear what this next action could be or discuss my answer to your question first?" The interviewer would see that you expect next steps and provide an answer which allows them to follow, but you should avoid running in the wrong direction, if your answer is not e.g. what the interviewer expected.
In case the interviewer asks "what would be your approach" or "how would you solve this", it might be a more candidate-led case, because the interviewer expects you to prepare a structured step by step approach to find a solution or recommendation. You should ask for a minute to think about the most relevant questions, write them down (potentially in a structured and content related way), then ask the questions and for another minute to think about her/his answers while preparing the step by step approach, you would like to present and discuss with the interviewer.
However, the case could also be both an interviewer-led and a candidate-led case: it might start with precise questions and continue with requesting a step by step approach. So it's always important to listen carefully what the interviewer tells you.
I hope this helps.