A 2015 Gallop poll of 15,747 U.S. adults who had a smartphone found that 72% checked their phones about once every hour. Based on these data we found the 95% confidence interval for the proportion of all U.S. adult smartphone users who check their phone about once per hour to be (0.713, 0.727). Suppose the sample size was 20,000 instead, while the proportion responding that they checked their cell phone about once every hour was still 72%. 

a. True or False? A 95% confidence interval based on these altered data would be narrower, because a larger sample size increases confidence, which in turn makes the interval narrower. 

b. True or False? A 95% confidence interval based on these altered data would be narrower, because a larger sample size decreases the variability of the statistic. 

c. True or False? A 95% confidence interval based on these altered data would be wider, because a larger sample size increases confidence, which in turn makes the interval wider. 

d. True or False? A 95% confidence interval based on these altered data would be wider, because a larger sample size increases the variability of the statistic