Which cube is a unit cube? A. a cube that is 3 meters long,3 meters wide,and 3 meters high b. a cube is a. that is 9 inches long,9inches wide,and 9 inches high c. a cube that is 1 yard long,1 yard wide, 1 yard high. d. a cube that is 11 centimeters long, 11 centimeters tall ,and 11 centimeters high ​