Sounds a lot like the first question you would be asked in a McKinsey interview. The best answers to this kind of question are specific. However, without a context, this is not possible.
Generally speaking, your variables are price and quantity. You can increase/decrease them to grow the topline. However, that's not a good answer and way too generic.
Depending on the specific context of the company i.e. business model, industry, product line, ownership structure, region, macro economic trends, strategy, balance sheet, etc., your answers should be tailored accordingly. When you take all these factors into account and manage to come up with specific and creative ideas, that's where you will impress people!
Hope this helps! Best of luck!