Hey!
I think this is one of those questions where they are mainly testing whether your reasoning is thoughtful and tailored, rather than whether you have a "perfect" reason for London specifically.
I would focus less on generic "London is exciting/fast-paced" points and more on what the London office means in the context of the firm itself. For example, you could mention that:
- The London office gives exposure to a broader range of national clients and large-scale matters
- Many of the firm's key sectors have strong links to London-based institutions
- You are interested in being at the centre of client interaction and collaboration across offices
- London aligns with your long-term career ambitions and where you see yourself building your professional network
I would also make sure to avoid sounding as though the regional offices are "lesser" options! Bevan Brittan is really strong outside of London, so it is better to frame it as why London suits you personally and professionally, rather than why the other offices do not.
I hope that assists!