The heart of this question is determining what work environment, or type of work, offers you the most job satisfaction. Primarily, they are trying to determine whether you are more of an introvert who thrives on more solitary tasks, or if you are more of an extrovert who prefers more collaborative and interpersonal work. There is no right or wrong answer here, and it is best to be honest. However, most people don't fall at either extreme of the scale, and fall somewhere in the middle, leaning in one direction or another. So it is as important for you to be as honest with yourself as you would be with your interviewer. Besides, the more adaptable you seem, the more desirable a candidate you will be.