Context: The passage below describes an experiment. Read the passage and then follow the instructions below.

Rudy used a dropper to put equal-sized drops of pure water, one at a time, onto a penny. The drops stayed together and formed a dome on the penny's surface. Rudy recorded the number of drops he could add before the water spilled over the edge of the penny. Then, he rinsed and dried the penny, and repeated the test using water mixed with hand soap. He repeated these trials on nine additional pennies. Rudy compared the average number of pure water drops to the average number of water drops mixed with hand soap that he could add to a penny before the water spilled over.
Figure: a dome of water on the surface of a penny.
Identify the question that Rudy's experiment can best answer.
A. Can pennies hold more drops of pure water or water mixed with hand soap?
B. Can pennies hold more drops of water mixed with dish soap or water mixed with hand soap?
Select the correct answer from the provided options and reply with the letter associated with it.

A