Final answer:
The control group in an experiment is designed to be identical to the test group save for the variable being tested, to ensure that any differences in the outcome can be attributed to that specific variable and support a causal relationship.
Step-by-step explanation:
The statement 'False. They hold different data although some may be the same' refers to the comparison between the control group and the test group in an experiment.
In a scientifically valid experiment, the control group and the test group should be as identical as possible, with only one variable being different. This variable is what the experiment aims to test.
The statement that they may 'hold different data' signifies that results may vary; however, the precise design of the experiment is to only manipulate one variable while keeping everything else constant to determine the effects of that one variable.
Option c. The control group must be identical to the test group except for one variable is the most accurate description of how control groups and test groups should be set up in an experiment.
If done correctly, any differences in the outcome between the test group and control group can be attributed to the variable being tested, thus supporting a causal relationship.
Your complete question is: False. They hold different data although some may be the same.