Your interviewer is curious about where your priorities lie. Primarily, they want to learn whether you prioritize your own goals above the goals of the team, which they'll be able to determine by whether your answer advertises you deserve all the credit for the team's success, or whether you took pride in the group's efforts, and your contribution to those efforts. Your answer needs to strike that fine balance of showcasing your merits through humility.
"To fulfill our mission of making our clients successful, we have to work together. Working together involves collaboration, cooperation, honesty and support... expectations we have of one another when working together."
