please help i choose D

Add two data points at 11. O O 0 8 O J 5 6 7 8 9 10 11 12 13 14 15 16 17 18 O O 0 8 O 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Which one of the following best describes how the changes affect the mean and standard deviation? O The mean does not change. The standard deviation does not change. O The mean does not change. The standard deviation is smaller. O The mean does not change. The standard deviation is larger. The mean changes, The standard deviation does not change. The mean changes. The standard deviation is smaller. O The mean changes. The standard deviation is larger