Why do we need to create and follow safety control in specific product?

Me with this i need to get the answer quickly.

In a study of a weight loss program, 40 subjects lost a mean of 3.0 lb after 12 months. does the weight loss program have practical significance? a. yes, because the weight loss program worked and the subjects lost a mean of 3.0 lb. b. no, because the mean weight loss of 3.0 lb after one year does not seem to justify the program. c. no, because the sample of 40 subjects was too small to determine if the program was useful. d. yes, because the mean weight loss of 3.0 lb after one year does seems to justify the program.

What is a good description of wellness