Answer:
The correct answer will be option D.
Step-by-step explanation:
In the given experiment of Jack and Damon- Jack heard the sentence better when he used balloon than without balloon suggests that sound waves traveled much clearer and faster than in open conditions as the air molecules packed inside the volume of the balloon are tightly packed or compact than the atmospheric gases.
The compact arrangement of the molecules of the air enhances the effect of the sound by providing a good medium to travel the sound waves.
Thus, option D is the correct answer.