According to researchers, the mean length of imprisonment for motor-vehicle-theft offenders in a nation is 17.2 months. One hundred randomly selected motor-vehicle-theft offenders in a city in the nation had a mean length of imprisonment of 18.5 months. At the 1% significance level, do the data provide sufficient evidence to conclude that the mean length of imprisonment for motor-vehicle-theft offenders in the city differs from the national mean? Assume that the population standard deviation of the lengths of imprisonment for motor-vehicle-theft offenders in the city is 6.0 months. Click here to view page 1 of the table of areas under the standard normal curve. Click here to view page 2 of the table of areas under the standard normal curve. Set up the hypotheses for the one-mean z-test. Ha: H O (Type integers or decimals. Do not round.) The test statistic is z=. (Round to two decimal places as needed.) Identify the critical value(s). Select the correct choice below and fill in the answer box within your choice. (Round to two decimal places as needed.) O A. The critical values are ±Zu/2 =+ O B. The critical value is z, =