Suppose data collected by observers at randomly selected intersections across the country revealed that in a sample of 40 drivers, 20 were using their cell phone. a. Give a point estimate of a, the true driver cell phone use rate (that is, the true proportion- or- population porportion- of drivers who are using their cell phone while driving). b. Compute a 99% confidence interval for it. c. Give a practical interpretation of the interval, part b. a. A point estimate for n is b. The 99% confidence interval for the population proportion a is (Round to two decimal places as needed.) c. Interpret this interval. O A. We are 99% confident that the population proportion of drivers using cell phones is inside this interval. O B. We are confident that 99% of the population do not use a cell phone while driving O C. We are confident that 99% of the population use a cell phone while driving. O D. There is a 99% percent chance that the population proportion of drivers who use cell phones is outside this interval