A study reports the mean change in HDL (high-density lipoprotien, or "good" cholesterol) of adults eating raw garlic six days a week for six months. This margin of error for a 95% confidence interval is given as plus or minus 6 milligrams per deciliter of blood (mg/dl). This means___________

A. The study used a method that gives a result within 6 mg/dl of the truth about the population in 95% of all samples
B. We can be certain that the study result is within 6 mg/dl of the truth about the population.
C. We can be certain that the study result is within 6mg/dl of the truth about the population if the conditions for inference were satisfied.
D. The study used a method that gives a result within 6 mg/dl of the truth about the population in only 5% of all samples.