This question affords you a chance to showcase the most relevant quality that the employer is looking for in you.
During the interview, you should be on the lookout for key qualities that they're looking. You'll have to use your own judgment to choose which quality is best. Whichever quality you choose, the message you want to get across is that there's no problem that you can't overcome. Where there's a will, there's a way. In developing your response, explain the situation, tell the tasks you completed to overcome the problem, and end with the result.
Some qualities that you may want to consider highlighting include: teamwork, a strong work ethic, or creativity.