You Want to Design a Controlled Experiment to Determine Which

You want to design a controlled experiment to determine which tablet, PEPCID AC or Alka-Seltzer, neutralizes stomach acid the quickest. Which of the following experiments would be the best to perform?

A) Place a PEPCID AC tablet in a beaker of acid at pH 2 and an Alka-Seltzer tablet in a separate beaker of acid at pH 2 and check the pH in the beakers every 2 minutes.
B) Take a PEPCID AC tablet at 8:00 am on Monday and take an Alka-Seltzer tablet at 8:00 am on Tuesday and take note of how long it takes you to feel better.
C) Find a group of your friends and go out to a big dinner. Then give half of them a PEPCID AC tablet and give the other half an Alka-Seltzer tablet and tell them to write down how long it takes them to feel better.
D) Place a PEPCID AC tablet in a beaker of acid at pH 2 and an Alka-Seltzer tablet in a separate beaker of acid at pH 2 and record how long it takes for the tablets to dissolve.