The purpose of this question is not to know about the challenges you have faced but to see your approach to manage them. Pick up an example of a challenge you faced at work and focus your answer on the steps to took to deal with it. Also, discuss about your learnings in the process.

For e.g. "Recently I was asked to recommend and implement the changes in the way the calls are distributed among my team members at the call centre. My team members were quite used to the way they were working and there was a lot of resistance to the proposed changes. I knew that these changes will improve the performance of the whole team so I discussed them with my manager and team in detail. I tried to win the confidence of the team members and explain them that it will be in the interest of all of us and the call centre if we implemented these changes. As they started seeing my point, it became easier to gain their support and the desired outcome. The result is that the customers get a reply faster and the performance of each team member has improved by more than 50%.