The point of this question is to not to separate yourself from the others on your teams nor to frame them as opponents. If you are performing at your best, the competition will be worried about you, not the other way around. Also, the best competitions are team friendly and collaborative in some manner, especially when the focus is a communal end goal. Think back to the times when you were in a friendly competition at work or were competing with yourself, trying to outperform your prior best. Comb through your background and your accomplishments to ensure you leave nothing on the table.
Detail how you rose to the challenge and were proud of your results. Every day you decide what attitude you'll embrace. The only thing you have control over is your attitude. In a team environment, the right attitude can go a long way. Consider these points when composing your answer.