4. To help consumers assess the risks they are taking, the Food and Drug Administration (FDA) publishes the amount of nicotine found in all commercial brands of cigarettes. A new cigarette has recently been marketed. The FDA tests on this cigarette yielded mean nicotine content of 24.2 milligrams and standard deviation of 2.9 milligrams for a sample of n=9 cigarettes. Construct a 95% confidence interval for the mean nicotine content of this brand of cigarette. O A. 24.212.187 O B. 24.2+2.364 O C. 24.2+2.319 O D. 24.2+2.229