A manufacturer claims that the mean lifetime of a new cutting blade is 2 years. Fourteen blades are randomly selected and their lifetime is measured. Assume the population follows a normal distributions with known standard deviation. Select the correct answer below: O The test is right-tailed because the alternative hypothesis is Ha : M > 2. The test is left-tailed because the alternative hypothesis is Ha : M 2. The test is two-tailed because the alternative hypothesis is Ha : u # 2