Matter is best described as existing in time and space, which allows us to understand its changes and physical locations. This option comprehensively captures how matter behaves and evolves in the physical world. Thus, the correct answer is B. time and space.
;
Matter is best described in terms of time and space, which encompass its physical location and temporal changes. While other descriptions like movement and shape are relevant, they are not as comprehensive. Therefore, the correct answer is B. time and space. ;