5. Randy's scenoe teacher is giving a demonstration to show how a metal reacts with different acids. He places a small piece of the metal in each of three beakers containing a solutions of three different
acids. He adds a plece of the metal to a fourth beaker that contains only water. What is the purpose of
the fourth beaker? 13.N.1.1)
A It ensures that the hypothesis will be correct.
B. It provides more data to include in a lab report.
C. It adds an Independent variable to the experiment.
D. It is the control and serves as the basis for comparison.