Here your interviewer wants proof that you will tackle problems head on and not just bury your head in the sand.

A strong answer will clearly demonstrate a problem, an action and a solution.

For example:

Problem: When I was first promoted to team leader, I consistently struggled to ensure that my team achieved their sales targets on a Friday.

Action: I sought the advice of more experienced team leaders to find out how they motivated their teams through the Friday slog.

Solution: Acting on the advice of the other team leaders, I implemented a combination of incentives over the next few weeks and successfully boosted my team's sales figures.