A. Distance . . . . . No. Distance is a scalar quantity. It has no direction.
B. Speed . . . . . No. Speed is a scalar quantity. It has no direction.
C. 30 m/s . . . . . No. 30 m/s is a speed without a direction, and I just told you that speed is a scalar quantity.
D. 9.8 m/s² down . . . YES ! It has a size AND a direction. It's a vector.
