This is a question which comes up in all job interviews. The best way to answer this is to pick a strength which is a requirement for the job.
An ideal in answer for a technical project manager or business analyst could be as follows:
I have a natural ability to communicate effectively with all members of staff in a way they understand. For example I’m able to speak to the stakeholder or client in a non-technical lingo. Whereas I’m able to draw on my technical background and communicate at a more detailed level with the software developers; when resolving issues I am able to ask the technical team the right probing questions to help steer the project back on track.