Ming wants to find out if air takes up space. Which experiment would best help her find this out? Choose the correct answer.

A. Fill a cup with water. Fill another cup with air. Weigh both cups.

B. Weigh an empty metal container. Place a lid on it. Weigh it again.

C. Blow up a balloon. Tie a knot to make sure it is closed. Try to flatten the balloon.

D. Put red food coloring in an empty bottle. Place a cap on the bottle. Shake the bottle to see if the air inside turns red.