A loaded question, as so many are! You need to make sure you are self-motivated to a considerable extent, so that you do not imply that the only way you ever do any meaningful work is if there are people around you telling you what to do. It is one thing to be a team player but another thing completely to be someone who needs other people to motivate you in order to get you to do things. It is possible that anyone who does well in a career or progresses rapidly within a company is able to motivate themselves to perform to the best of their abilities and does not need other people around them to do this. Obviously people need other people around them often to make sure they remain motivated and focused, but a lot of motivation and perseverance comes from within. Make sure you get this across and distinguish between the inference in this question that you may not be able to motivate yourself and thus succeed from the question as to whether you are a team player or a loner or someone who prefers to work on their own.
Examples of Answers
“I am a self-motivated person who works well in a team or individual environments. You can see from my CV that I have had jobs in the past where I have been a member of a team as well as jobs where I have worked on my own. I enjoy being around others and working as part of a team but I am happy to motivate myself to succeed without needing others to encourage me to do so.”