Answer:
The correct answer is:
Includes at least two groups, one of which does not receive the experimental treatment. (B)
Explanation:
A controlled experiment is made up of at least two groups of participants (subjects). One group (the test group) receives the experimental treatment, which can be an intervention or a new drug to be tested etc, and the effect of the treatment on the subjects is measured, while the second group of similar subjects also known as the control group acts as a baseline and do not receive the treatment or intervention. They act as a baseline to ensure that the change observed in the treatment group was brought about as a result of the treatment.
<em>Note that repeating the experiment several times does not ensure accuracy of the result, rather it ensures reliability of the results hence option D is not correct</em>
A
B is wrong because mitochondria would likely absorb the stain even if it was dead.(And most cells that have been treated are dead anyway). C and D are just throwaway answers, you usually want to avoid the word "always" when drawing conclusions.
I have 6 but here they are:
01.) Iron Deficiency
02.) Iodine Deficiency
03.) Vitamin B Deficiency
04.) Vitamin B12 Deficiency
05.) Calcium Deficiency
06.) Vitamin A Deficiency