Scientists were conducting a multiyear study on the effectiveness of a new drug for long-term memory loss. They gave some of the test subjects the new drug to find out if it improves their long-term memory.Which is a possible limitation of this study?
A
Test subjects may want to participate in additional experiments.B
Test subjects may find that the drug is not effective.C
Test subjects may get bored and want to quit early.D
Test subjects may have full-time jobs.